Tables for the determination of minerals by means of their physical properties, occurrences, and associates
Tables for the determination of minerals by means of their physical properties, occurrences, and associates by Kraus, Edward Henry (1911). Full text and…
Public-domain full text preserved in the Mountain Man Mining Library. Original source: archive.org.
at |: .com/I
ijGooglc
Hf 2 5-0
joogle
ijGoogIc
ijGoogle
Tables
For The
Detekmination Op Minerals
ijGoogle
published the
McGroTv- Hill Book- Company
Ne'v Yorlt
fiuccMaora to thcDookDeparimenU oF the
McGrawPubUahing Company Hill PuULshin Company
[\1bli3hers of books for
Electrical World The Engineo'ing and Mining Journal
Enneenng Record H>iver and ITie Enneer
Electric luilwy Journal American Mocninijt
MetallurcaJ and Clieinical Engineering
:y
Tables
Determination Of Minerals
By Means Of
Their Physical Properties, Occurrences, And Associates
EDWARD HENRY KRAUS, Ph. D.
And Walter Fred Hunt, A. M.
McGRAW-HILL BOOK COMPANY 239 WEST 39TH STREET. NEW YORK
a BOUVERIE STREET, LONDON, E. C.
:y
' Cdllebe J
Copyright, 1911 - McGraw-Hill Book Company
:y
prefa(;e.
The successful determination of minerals at sight depends upon the ability to make quick and accyrate distinctions between the physical properties, occurrences, and associates of the several minerals which may be suggested by the luster, color, form, streak, and hardness, especially, of a given specimen. As a result of extensive experience in the laboratory and field, luster and color have been made the fundamental basis of these tables, further subdivisions being introduced by the streak and hardness. Minerals with similar physical properties are thus grouped together, aiding the student materially to acquire the necessary facility to make rapid distinctions.
The tables include 250 of the most common minerals, classified into three groups, which may be designated as (1) very common, (2) common, and (3) not common, but important. The display given to the name of a mineral indicates at a glance in which of the above groups it has been placed. Page references to several textbooks on mineralogy will be found of great convenience when more detailed descriptions are desired than obviously can be given in determinative tables.
\Vc have drawn freely upon all possible sources but are under especial obligations -to Weisbach, Ktockmann, Crosby, and Eakle, whose tables were constantly before us.
MlNBBALOGICAL LaBORATOST, EDWARD H KrAUS,
University of Michigan, „, '
February, 1911. WALTER F. HuNT.
:y
ijGoogle
Table Of Contents.
Preface v
Introduction. — Physical Properties — Luster, Color, Streak, Hard- ness, Crystallization, Structure, Cleavage, Parting, Fracture, Specific Gravity, Tenacity, Transparency, Taste, Odor, Feel or
Touch, Magnetism x
Glossary 7
General Classification and Analytical Key 14
Minerals with Metallic Luster 16
Minerals with Non-metallic Luster 68
Index 249
:y
ijGoogIc
Introduction.
Physical Properties.
The physical properties of moat importance in the determination of minerals at sight, without the aid of blowpipe or chemical reactions, will be described briefly. AH terms given in the introduction or used in describ- ing minerals in the tables are defined in the glossary, page 7.
Luster. — The luster of a mineral is the appearance of its surface in reflected light, and is a property of fundamental importance in the rapid determination of minerals. The luster and color of minerals may usually be easily recognized at first sight.
Lusters may be divided into two large groups: metallic and non-metal- lic. Tlie metallic luster is indicative of metals and is exhibited by min- erals which are opaque or nearly so. All other lusters may be designated aa non-metflllic, some of these being described as vilreoiix or glassy, ada- mantine, resinous or greasy, pearly, silky, dull, earthy, splendent, and so forth.
Color. — The color of a mineral is one of the first physical properties to be observed. Some minerals have a fairly constant color, while in others it may vary greatly, due to the presence of pigments, inclusions, or other impurities. The terms used in describing the various colors need no explanation.
Streak. — This is the color of the fine powder of a mineral and is one of the most important physical properties for the determination of minerals. Although the color of minerals may vary greatly the streak is often fairly constant. The color of the streak may be determined by crushing, filing, or scratching. The usual and most satisfactory method, however, is to rub the mineral on a piece of white, unglazed porcelain, the streak plate. The ease or difficulty with which the streak is obtained is to some extent indicative of the hardness of a mineral.
Hardness. — -The resistance offered by a mineral to abrasion or scratch- ing is termed hardness. It is indicated relatively in terms of Mohs's scale, which consists of ten common minerals arranged in order of in- creasing hardness, as follows:
1. Tale, 0. Feldspar,
2. Gypsum, 7. Quartz,
3. Catcite, 8. Topaz,
4. Fluorite, 9. Corundum,
5. Apatite, 10. Diamond,
:y
2 Introduction.
Beryl, 7.5 to 8 in hardness, is often aubstituted for topaz in the above scale.
Substances, scratched by and which in turn scratch some one member of the scale, are said to have the hardness assigned to that member. In determining the hardness of a mineral the scratch made should be short as possible, not over 1/4 inch, and care exercised to distinguish between a scratch and a chalk mark, the latter being easily removed by rubbing.
The determination of the approximate hardness is greatly simplified by using the finger nail, copper coin, and the knife blade, which possess the following values :
Finger nail, up to 2.5 Copper coin, up to 3 Knife blade, up to 5 . 5.
Since the majority of the minerala are less than 6 in hardness, this simplified scale is of great convenience in determining the approximate hardness in the laboratory and field.
In the tables which follow on page 14, minerals have been divided into three groups based upon the hardness of two very common minerals, calcite and feldspar, thus : (1) 1 to 3, softer than or as hard as calcite; (2)
3 to 6, harder than calcite but not harder than feldspar; (3) over 6, harder than feldspar.
Crystallization. — Minerals are described in the tables as occurring in crystals or masses. Crystals are bounded wholly or in part by natural planes and may be divided into six groups called the crystal systems. Massive minerals are either crystalline or amorphous.
The crystal systems are characterized by their axes.
Cubic System. — Three equal and perpendicular axes. Some forms are the cube,* octahedron, dodecahedron, tetrahcxahedron, tetragonal trisoc- tahedron, hex octahedron, tetrahedron, and pyritohedron.
Hexagonal System. — Four axes, three of which are equal and horizon- tal, intersecting at 60°. The fourth is vertical, perpendicular to, and either longer or shorter than the horizontal axes. Common forms are prisms, bipyramids, pyramids, basal pinacoid, rhombohedron, and scalenohedron.
Tetragonal System. — Three axes, two of which are equal, horizontal, and perpendicular to each other. The third axis is vertical, perpendic- ular to, and either longer or shorter than the horizontal axes. The important common forms are prisms, bipyramids, pyramids, basal pina- coid, and bisphenoid.
For a fuller description of Home of the following Mrm? see OieBlossary, poge7; a>o consult any standard textboo' ' "
,,-z=c B.
Introduction. 3
Orthorhombic System. — Three unequal and perpendicular axes. The axis extending from front to rear is the brachyaxia, the one from right to left the macroaxis, while the third is the vertical axis. The names of the cryst alio graphic forms often indicate the axis to which they arc parallel. Some common forms are prisms, bipyramids, pinacoids, and domes.
Monodinic System,— Three unequal axes, two intersect obliquely, while the third is perpendicular to them. The axis from front to rear, held inclined to the observer, is the clinoaxis, the one from right to left the orthoaxis, while the third is the vertical axis. The common forms are prisms, hemipyramids, domes, hemidomes, and pinacoids. The specific names often indicate the axis to which the forms are parallel.
Triclinic System. — Three unequal and inclined axes, designated as in the orthorhombic system. Common forms are tetrapyramids, hemi- , hemidomes, and pinacoids.
Structure. — Most minerals occur in masses without any definite crys- tal outline and are said to bo crystalline or amorphous. Crystalline aggregates or masses are made up of closely packed crystalline grains of irregular form, while amorphous substances are entirely devoid of crys- tallinity. Some of the more common and important terms used in de- scribing the structure of massive minerals are: adcular, botryddal, bladed, capillary, deavable, columnaT, compact, cryptocrystalline, Jibrous, foliated, lamellar, mammillary, phanerocrystalline, reniform, and stalactitic. These and other terms relating to structure are defined in the glossary, page 7.
Cleavage .M any minerals split or separate easily along definite planes. This property is called cleavage, and is often very conspicuous and highly characteristic. The planes along which the separation takes place are parallel to possible crystal faces and so designated. Thus, octahedral cleavage signifies that the splitting takes place parallel to the faces of the octahedron. The manner and ease with which cleavages are obtained can be indicated by such terms as, perfect, imperfect, distinct, indistinct, easy, and so forth.
Parting. — This is a false cleavage and usually takes place parallel to twinning planes.
Fracture. — The fracture of a mineral refers to the character of the surface obtained by breaking crystalline substances in directions otherthan those along which cleavage or parting may take place, or amorphous sub- stances in any direction. The various fractures are described as, con- choidal or shell-like, even, uneven, hackly, spliniery, or earthy.
Specific Gravity. — The specific gravity of a solid substance is its weight compared with the weight of an equal volume of water. The specific gravity of minerals can be determined most conveniently by means of the
:y
Inthoduction.
recording Jolly balance* recently devised by Professor F. H. Kraus. This balance consists of the square upright tube T to which the fixed vernier M and the movable graduated scale X are attached, as shown in the accompanying figure. T contains a second tube Z which can be moved by the milled-head A. The vernier N is attached to Z by the arm E. Screw B controls the rod H,, movable within the tube Z. From R the spiral S and scale pans C and D are suspended, the thin wire rods W and V connecting the spiral
and pointer
the
pans with which, set in jewelled bearings, swings freely in front of a small cir- cular mirror.
To determine the specific gravity of a mineral, it is necessary that the graduated scale X, verniers M and N, and the pointer P all be at zero, the lower scale pan D being immersed in water. P is brought to the zero point by being made to coincide with the mark on the mirror, the adjustment being accom- plished by the screw B. A fragment of the mineral is now placed on the upper pan C, and the elongation of the spiral noted by again bring- ing the pointer P to the zero position. This is done by turning the milled-head A, and moving the tube Z and graduated scale X upward. After the zero position is obtained the scale is clamped by the screw Y. The reading at M gives obviously the elongation of the spiral due to the weight of the mineral in air. The fragment is now transferred to the pan D under water, care being taken to avoid air bubbles adhering to it. The pointer P is again, for the third time, brought to the zero position by moving the tube Z and attached vernier N downward by turning the bead A. The reading at N indicates directly the loss in the elongation of the spiral, due to the immersion of the fragment in water. If the weight of the
mporten of
ijGoogle
Introduction. 5
specimen in air be represented by W, the reading at M, and the loss of weight when immersed in water by L, the reading at N, we have,
W
Specific gravity -
The advantages of this balance over others in common use are that the elongations of the spiral for the weight of the specimen in air and loss of weight when immersed are recorded, and further only two readings and a simple division ar necessary to obtain the specific gravity, which is generally accurate to within a few units of the second decimal. The whole determination ought not to require more than two minutes.
Tenacity. — Under this heading is included the behavior of a mineral when an attempt is made to break, cut, hammer, crush, bend, or tear it. The following well-known terms are used: elastic, flexible, JHable, brittle, inelaBlic, tough, sectile, -malleable, and ductile.
Transparency. — This is the ability to transmit light and is of minor importance in the determination of minerals by means of their macro- scopic physical properties. Substances through which objects can be easily and distinctly seen are said to be transparent, those through which no light appears to pass, even in very thin layers, opaque. Between these extremes we may distinguish subtransparent, transluceM, and subtrans- lucent substances.
Taste. — Minerals soluble in water or the saliva generally possess a characteristic taste, which may be described as astringent, saline or salty, alkaline, pungent, metallic, cooling, bitter, acid, or sour.
Odor. — Some minerals give off characteristic odors when breathed upon or heated by being rubbed, scratched, or pounded. These odors are arsenical or garlic, sulphurous, bituminous, fetid, and agriUaceous or clay-like.
Feel or Touch. — The impression one receives by handling or touching a mineral is called the feel or touch. It is designated as smooth, greasy, or Boapy, harsh or meager, or cold.
Magnetism. — Comparatively strong magnetism is shown by a few iron-bearing minerals, their powders or small fragments being readily attracted by a magnet. A convenient method to test the presence or absence of magnetism in a mineral, without crushing it, is to suspend a small horseshoe magnet from the finger so that it may swing freely and then bring the specimen under consideration close to the magnet. If the specimen is magnetic the magnet will be deviated from its vertical posi- tion, the amount of the deviation indicating roughly the relative strength of the magnetism.
:y
ijGoogle
Glossary.
The glossary contains all terms given in the introduction or used in describing minerals in the tables.
Adcular — needle-like.
Acute — sharply pointed.
Adamantine luster — tike that of the diamond, or oiled glass.
Aggregate — mass, cluster, group.
Alkaline taste — like that of soda.
Alluvial — relating to deposits made by flowing water.
Amorphous — devoid of crystallinity.
Amygdaloid — igneous rock containing small cavities, which are filled entirely, or in part, with minerals of secondary origin.
Arborescent — branching, tree-like.
Astringent taste— causing contraction or puckering.
Basal — parallel to the basal pinacoid.
Basalt — basic igneous rock, dark and compact,
Bipyramld — two pyramids placed base to base,
Blsphenoid — four-sided form of the tetragonal system, each face being an isosceles triangle.
Bladed — elongated and flattened, like a knife blade.
Botryoldal — closely united spherical masses, resembling a bunch of grapes.
Bracbypinacold — form with two faces in the orthorhombic or triclinic systems, parallel to the brachy and vertical axes.
Brittle — crumbles under knife or hammer, cannot be cut into slices.
Capillary — hair-or thread-like.
Cellular — porous, like a sponge.
Chatoyant— having a changeable, undulating, or wavy color or luster.
Clastic — made up of fragments.
Clay— fine soft, aluminous sediments that are plastic.
Cleavable — capable of cleaving or splitting in definite directions.
Cleavage — property of many crystalline substances of breaking or splitting in definite directions, yielding more or less smooth surfaces.
Clinopinacold — form with two faces in the monoclinic sytem, parallel to the clino and vertical axes.
jyGoogle
8 Gl0S8Ary.
Columnar — long thick fibers, often parallelly grouped.
Compact — closely or firmly united.
Complex crystals — highly modified, having many crystal forms or faces.
Concentric — spherical layers about a common center, similar to layers of an onion.
Coochoidal — curved, shell-like.
Concretion — rounded mass formed by accumulation about a center.
Concretionary — formed as a concretion.
Confused — indistinct, jumbled together.
Conglomerate — sedimentary rock, composed of rounded fragments, coarse or fine.
Contact mineral — formed under the influence of an igneous intrusion.
Crested — tabular crystals arranged in ridges.
Cruciformn the form of a cross, cross-shaped.
Cryptocrystalllne — finely crystalline, revealed only under the micros- cope.
Crystal — substance bounded, entirely or partially, by natural plane surfaces.
Crystalline — having crystal structure, but without definite geometri- cal form.
Crystallization — process of solidification in the form of well developed crystals, or in crystalline masses.
Cubic system — see page 2.
Cubical — with the form of a cube.
Cyclic — repeated twinning yielding circular forms.
Dendritic— branching, fern-like.
Dlchroism — property of exhibiting different colors by transmitted light when viewed in two directions.
Disseminated — scattered through a substance.
Divergent— radiating from a center.
Dodecahedral — pertaining to the rhombic dodecahedron, a form with twelve faces in the cubic system.
Domatlc — relating to a dome, a horizontal prism.
Drusy — rough surface due to a large number of small, closely crowded crystals.
Ductile — capable of being drawn into wire. Ductile substances are also malleable and sectile.
Dull luster — not bright or shiny.
Eartby — without luster, dull.
Efflorescence — thin crust or coating, often powdery.
Elastic — resumes original position when displaced.
:y
Gl088Ary. 9
Eruptive rock — formed by the solidification of a surface flow of molten rock. Often used aa a synonym of igneous.
Etched — corroded.
Felted — fibers closely matted.
Ferruginous — containing iron.
Fibrous — consisting of slender fibers or filaments.
Fissure — crack or crevice.
Flexible — capable of bending without breaking, and does not resume original position when the force is removed.
Fluorescence — property of showing different colors in reflected and transmitted light.
Folia — having the form of thin plates or leaves.
Foliated — in plates or leaves which separate easily.
FoESlllferous — containing or composed of fossils.
Fracture — refers to surface obtained when breaking in a direction other than parallel to cleavage or parting.
Friable — easily crumbled or reduced to powder.
Furrowed — deeply striated, grooved.
Gangue — associates of more valuable minerals or ores.
Globular — spherical or nearly so.
Gneiss — laminated or foliated metamorphic rock consisting usually of quartz, feldspar, and mica.
Granite — coarsely crystalline igneous rock, consisting usually of quartz, feldspar (orthoclase), and mica or hornblende.
Granular — consisting of closely packed grains, either coarse or fine.
Guano — excrement of sea fowl.
Habit — development or form of crystals.
Hackly — rough surface, covered with sharp points.
Hardness — resistance offered to abrasion or scratching. See page 1.
Hemlmorphlc — having different planes about the two ends of a crys- tallographic axis.
Hexagonal sjrstem — see page 2.
Hexoctahedron — form of the cubic system having forty-eight faces.
Hopper shaped — cavernous and tapering, square funnel shaped.
Hygroscopic — property of absorbing moisture from the atmosphere.
Igneous rock — one formed by the solidifaetion of a molten mass from within the earth.
Impregnated — finely disseminated and intimately mixed with rock.
Impressed— marked by pressure, indented.
Inclusion— foreign material enclosed within a mineral.
Incrustation — crust or coating on another substance.
Inelastic — not elastic-
:y
Interlaced
, r intertwined, confused,
Interwoven ' '
Iridescence — showing play of colors, usually due to thin film or coating.
Klmberlite — altered, very basic igneous rock, consisting essentially of serpentine, olivine, augite, pyrope; sometimes diamond-bearing.
small, thin plates or layers, curved or straight.
Lamellar — consisting of lamelhe or laminae.
Lava — molten rock, especially surface flows; also applied to the solid- ified product.
Lenti cular — lens-sh aped .
Limestone — rock composed essentially of calcium carbonate, calcite.
Luster — manner in which the surface reflects light.
Macroplnacoid — forrn with two faces in the orthorhombic or triclinic systems, parallel to the macro and vertical axes.
Macroscopic — visible to the unaided eye, opposed to microscopic.
Malleable — capable of being flattened by hammering.
Mammillary — rounded mass, larger than that of a grape.
Massive — without definite crystal form; either crystalline or amor- phous.
Metallic luster — similating a metal and exhibited by minerals which are opaque, or nearly so, and quite heavy,
Metalloidal — having the appearance of a metal.
Metamorphlc rock — one that has been altered by heat, pressure, liquids, or gases, so as to render its texture either crystalline or schistose.
Meteorite — mass of stone or iron which has fallen to the earth from outer space.
Micaceous — composed of very thin plates or scales, like those of mica.
Modified, highly — consisting of a large number of crystal forms or faces.
Monoclinlc system — see page 3.
Mottled — spot ted .
Multi-colored— having many colors.
. . rounded mass of irregular shape.
Nugget — rounded, irregular lump, especially of a metal. Ocherous — earthy, and usually red, yellow, ~or brown in color. Octahedral — pertaining to the octahedron, eight-sided form of the cubic system.
Oolitic — rounded particles the size of fish-eggs.
:y
GLOaaAHY. 1 1
opalescent — with milky or pearly reflections.
Opaque — will not transmit light even through thin layers or edges.
Oithopinacoid — form with two faces in the monoclinic system, parallel to the ortho and vertical axes.
Orthorhombic system — see page 3.
Parting — false cleavage, usually the result of twinning.
Pearly — similar to the luster of the mother of pearl.
Peat— dark brown to black substance, formed by the partial decom- position of vegetable tissue in marshes.
Pegmatite — very coarse grained acid igneous rock, consisting essenti- ally of quartz, feldspar, and mica.
Peildotite — very basic igneous rock, composed largely of olivine and augtte.
Pbanerocrystalline — crystals or coarsely crystalline.
Phonolite — compact extrusive igneous rock, consisting essentially of orthoclase, nephelite, and pyroxene.
Plnacoidal — relating to forms with two planes, parallel to two or more cryatallographic axes.
Plsolltic — composed of small, rounded masses, the size of peas.
Pitchy — resembling pitch.
Placers — sands and gravels containing minerals of economic impor- tance.
Plfutlc — capable of being molded or shaped.
Plates — broad, relatively thin masses.
Platy — consisting of plates.
Plumose — feathery.
Pocket — cavity in a rock, often filled with minerals.
Prismatic — elongated parallel to one of the crystallographie axes, usually the vertical axis.
Pseudo — false.
J 1, ( possessing the geometrical form of another mineral.
Pungent — sharp, biting.
Pyramidal — pertaining to the pyramid, a form which usually inter- sects three crystallographie axes.
Pyritohedron — form of the cubic system with twelve, five-sided faces.
Rectangular — intersecting at 90°.
Refraction, double — yielding two refracted rays.
Reniform — large, rounded masses, kidney-shaped.
Resinous — luster of resin, greasy,
Retlculatedfibers crossing like a net.
Rhombic — diam ond-shaped.
:y
12 Gl088Ahy.
Rhombohedral — relating to the rhombohedron, a form of the hexag- onal system, with six faces intersecting at angles other than 90°.
Rosette — simulating a rose.
Saline— salty.
Sandstone— sedimentary rock conaiating of consolidated sand.
Scalenohedral — relating to the sealenohedron, a twelve-sided form of the hexagonal system, each face being a scalene triangle.
Scaly — consisting of scales.
Schiller— peculiar bronze-like luster.
Schist— metamorphie rock with foliated or parallel structure, splitting easily along certain planes.
Seam — narrow vein.
Sectile— capable of having slices cut off.
Semi-opaque — between opaque and transparent.
Shale — laminated sedimentary rock, consisting of hardened muds, silts, or clays.
Sheai-llke — resembling a sheaf of wheat.
Silky — luster of silk, due to fibrous structure.
Skeletal — pertaining to crystals with incomplete development of their faces, often with cavernous appearance.
Slate — dense, fine grained metamorphie rock, which splits easily into broad, thin layers or sheets.
Splendent — very bright by reflected light.
Splintery — breaking into splinters.
Stalactltlc — cylindrical or conical masses resembling icicles.
Stalky — consisting of long, stout fibers.
Stellate— -radiating from a center producing star-like forms.
Streak — color of fine powder, usually obtained by rubbing the min- eral on unglazed porcelain.
Structure — see discussion page 3.
SubadamantiDe — im perfectly adamantine.
Subconcholdal — imperfectly conchoidal.
Sublimation — direct solidification from a vapor.
Submetallic — imperfectly metallic.
Syenite— granular igneous rock, commonly consisting of orthoclase, and hornblende or biotite.
Tabular— flat, tablet-like.
Tarnish' — -thin film formed on the surface when exposed to air and <lifferent in color from that of the fresh fracture.
Tenacity — see discussion page 5.
Terminations — faces on the end of a crystal.
Tetragonal system — see page 2.
:y
Glossary. 13
Tetragonal trisoctahedron — form of the cubic system with twenty- four trapezohedral faces.
Tetrahedral — pertaining to the tetrahedron, a four-sided form of the cubic system.
Tetrahezahedron — form of the cubic system with twenty-four trian- gular faces.
Tough — not easily broken.
Translucent — when light passes through, but objects can not be seen distinctly.
Transparency — refers to the amount of light passing through a sub- stance.
Transparent — when sufficient light passes through the substance so that objects may be distinctly seen.
Trap — dark basic, fine grained igneous rock.
Tricllnic system — see page 3.
Trillings — iiitergrowth of three crystals in a symmetrical manner.
Twinned — crystals consisting of more than one individual, arranged in a definite manner.
Twins — symmetrical intergrowth of two crystals.
Variegated — with different colors.
Vein — crack or fissure, partially or completely filled with mineral matter.
Tfltreous luster — like that of glass.
Warty — small, rounded masses resembling warts.
Waxy — luster of wax.
Zonal — in zones or layers.
:y
GENERAL CLASSIFICATION A. HDfERALS WITH METALLIC LUSTER
Color of mineral
HudneM Pagp
. Dark gray or black. .
2. HetalUc white or me- taiUcgraj
4. Brass, bronze, or copper red '
5. Red, brown, or blue . .
White, gray, green, red, brown, „ , -,
, f 1 to 3
Black I „
r 1 to 3
Metallic white or steel gray „
mi / lto3
Black „ „
Gray, brown, or yellow 1 to 6
Black Over 3
Gray, red, or yellow 1 to 3
Black Over 3
White, gray, green, red, brown I ftf:
[ Over 6
Black 1 to6
:y
And Analytical Key.
B. Minerals With Hoh-Hetallic Luster
Color of mlneTBl
Hordnem Page
Dark gnj or black . .
2. Pink, red, or red violet . .
. Green, blue, or blue violet. .
4 . Yellow or brown . .
Uncolored, white, or light gray.
Piok, red, brown, or yeUoi
Uncolored, white, or light gray.
Uncolored, white, or light gray.
Red, brown, yellow or black . ,
Uncolored, white, or light gray.
1 to3 3 to 6 Over 6
I to 3 3 to 6 Overs
1 to3 3 to6
Over 6
5. Colorless, white, or light /
Uncolored, white, or light gray, .
DigizjcCyGoOle
A. Ubbrals With Metallic Luster
StreakWhite, gray, green, red, , or yellow
Name, Compoaition, and References
Ozocerite (Mineral
Cryatalliiation
Structure Luster
Crystals -C I Transparency
Massive — M 1
Never in crystals M— Compact, fibrous, lamellar
Subraetallic Black Waxy Brownish
Translucent black
, Danon Panaiu
Wad MnO„ H,0, etc.
Amorphous 7 Dull
H — Earthy, sometimes Submetallic with globular struc- Opaque
Brownish
black Black
Lignite (Brown coal)
Amorphous
Dull
Black
M— Compact, fibrous;
Opaque
Brownish
C, H, 0, etc.
black
202. 54fl,
3S
woody structure
REHATrTE, variety
Hexagonal
Metallic
Iron black
Specuiar %
ron ore
C— Thin tabular, often
Splendent
Dark steel
Pe,0,
in parallel position M— Scaly, micaceous,
Opaque, to
translucent
gray
Se, 334.
platy, foliated Monoclinic
BIOTITE (Black mica)
Submetallic
Black
C— Tabular, with hex-
Pearly
Brownish
(K,H),(Mg,Fe),(Al,Fe)
(SiO.),
agonal or rhombohe-
Opaque to
black
dral habit
transparent
Greenish
black
215. 467.
scales
Pyniyrite
Hexagonal
e-mail, complex,
Metallic Adamantine
Dark lead
hemimorphic, rare M— Compact, dissemi-
Opaque to transparent
nated, bands, crusts
Silver
Cubic
Metallic
Dark gray
C — Small, often distorted
Opaque
black a
Ag
H — Grains, scales, plates, twisted hair- or wire- like forms
expos
others
logy, IBlirAi ArtwrrOan orMiuerioy',"l898
New York; K
ijGoogle
1. DARK GRAY OR BLACK HI COLOR HardneBB 1 to 3
ClumcteriBtics a ad
Aaeociatee
fingers; may be
Easily indented by Soger nail. Reaembles impure wax. Greasy feel. In sandstones and shales. With petroleum and coal.
2.6 White 3, Grayish
2.6 Cherry red 3. Purplish red
2.6 Silver white 3. Light lead gray
F— Conchoidal
Brittle to tough
C— None, but dis- tinct parting F— Uneven Brittle to elastic
C — Basal, perfect, conspicuous
Tough, laminie of fresh biotite very elastic
C — Imperfect F— Conchoidal Brittle
F— Hackly Malleable, ductile
Very soft varieties soil fingers. Apparently very light and floats on water, due to porosity. Usu- ally adheres to tongue. With psilomelane, pyrolusite, sider- ite, limonite.
More or less carbonized plant re- mains. May disintegrate on ex- posure. Jet, compact, coal black variety with resinous luster.
Bright, shiny scales, often loosely compact; foliated or micaceous masses. In metamorphic rocks or as sublimation product around volcanoes.
Easily recognized by structure, highly perfect cleavage, and elasticity. Important constitu- ent of many igneous and meta- morphic rocks — granite, syenite, gneiss.
Frequently as gray or dark red bands, known as dark rvby silver ore. With proustite; in veins with other silver minerals and galena.
Color and streak darken on ex- posure. With silver, lead, ar- senic, cobalt, and nickel min- erals — argentite, pyrargyrite, proustite, smaltite, galena; also fluorite, calcite, barite.
d PatBOus, UiDekicy. Revised Edition
ijGoogle
A. Hiherals With Metallic L0Ster
Streak— White, py, green, red, brown, or yellow
Crystallization
Structure
Luster
Color
References
Crystals -0 Massive
Transparency
Tetrahedrtte
Cubic
Metallic
Dark steel
Cu,Sb,S,
C— Tetrahedral, often
Opaque
gray
highly modified
Iron black
KrauB. Daoa, Parsons
nraninlte (Pitchblende)
Cubic
Pitch-like
Pitch black
C— Octahedral, rare
Submetallic
Brownish
U0„ U0„ PbO, etc.
M — Botryoidal, columnar
Dull
black
curved lamellar, gran
Opaque
Greenish
ular, compact; appar-
black
142. 521. 27a
ently amorphous.
AUbandite
Cubic
Submetallic
Iron black
C— Rare
Dull
MnS
M— Granular, compact
Opaque
34. 292, 22S
Siderite
Hexagonal
Brownish
C— Rhombohedral, curv-
Dull
black
FeCO.
ed or saddle-shaped,
H — Cleavable, granular, compact, botryoidal,
Opaque to translucent
Black
118. 359. 223
rarely fibrous
SPHALERITE (Black Jack)
Cubic
Submetallic
Black
Resinous
Yellowish
ZnS
often very complex
Opaque to
black
M— Compact, cleavable,
Brownish
fine or coarse gran-
black
33. 391. 242
ular
Hanganite
Orthorhombic
MetaUic
Iron black
C — Columnar, prismatic,
Dark steel
MnO.OH
vertically striated ; often in groups or bundles
Opaque
gray
93. 349. 230
stalactitic
♦Cuprite
Cubic
Adamantine
Reddish black
C —Octahedrons, dodeca-
Dull
Black
Cu.O
hedrons, alone or in
Translucent
combination
to opaque
88, 331. 288
M— Granular, earthy
Uacommou color.
:y
1. Dark Gray Or Black In Color
Hardnesa 3 to C
Fracture — F Tenacity
Specific Gravity
Reddish brown
C— Indistinct
Crystals have characteristic tet-
F— Uneven Brittle
rahedral habit. Sometimes coated with chalcopyrite. With. sphalerite, galena, boumonite, chalcopyrite, siderite.
Dark browD
F— Conchoidal, un-
Pitch-like appearance and frac-
Olive green
Brittle
ture important. Fresh material is hard and heavy. With ores of lead, silver, and bismuth; also thorite, orthite, fergu- sonite.
0!ive green
C— Cubical, not con-
Color may tarnish brownish
spicuous
black. Streak characteristic.
F— Uneven
With rhodochrosite, galena, py-
Brittle
rite. argentite, sphalerite.
Yellowish
C— Rhombohedral,
Distinguished from sphalerite by
brown
perfect, conspic-
F— Conchoidal
Brittle
3,9
curved crystals and rhombohe- dral cleavage. In ore deposits; beds and concretions in lime- stones and shales. With pyrite, chalcopyrite, galena, tetrahe- drite, cryolite.
S.6
Dark brown
C— Dodecahedral,
Color and streak vary with im-
Yellowiah
perfect, usually
brown
conspicuous
stone. With galena, chalcopyrite.
Grayieh
F — Conchoidal Brittle
pyrite, barite, fluorite, siderite, rhodochrosite.
Reddish brown
C-— Brach ypinacoida 1 ,
Altera easily to pyrolusite, hence.
Blackish
perfect
surface may give black streak.
brown
F— Uneven
Brittle
With other mangauiferoua min- erals; also barite, calcite, sider- ite.
Brownish red
C— Indistinct
Easily recognized by associates.
Dirty brown
F— Uneven Brittle
6,1
Usually with other copper min- erals—malachite (green), azu- rite (blue), chalcocite and melac-
onite (black), native copper.
ijGoogle
A. Mbtebals With Metaluc Luster
Streak— White, gray, green, red, brown, or yeUow
CrystallJEation
Name, Composition, and
Structure
Luster
References
Crystals
Massive -M
Transparency
'Thorite (Orangite)
Tetragonal
Submetallio
Black
C— Square prisma with
Vitreous
Brownish
ThSiO.
bipyramida
Opaque to
black
M™
M— Compact, dissemi-
translucent
Kmus. Dana,
nated
Goethite
Orthorhombic
Brownish
C— Small, thin tabular,
Translucent
black
FeO.OH
needle-like; paral- lelly grouped or in scaly, fibrous, vel- vety crusts
to opaque
Black
B3. 349,
H— Reniform, stalactitic
TTTAinTE (Sphene)
Monoclinic
Submetallio
Black
C— Wedge- or envelope-
Vitreous
Brownish
CaTiSiO.
shaped when dis- seminated, tabular or
tached
Opaque to translucent
black
371. 485,
H — Compact, lamellar
LDfOHITE
C— Always pseudo-
Metallic
Black
Dull
Brownish
Fe.O,(OH),
atter pyrite, marca- site, siderite M— Compact, stalactitic. botryoidal, reniform; often with internal, radial fibrous struc-
Opaque
black
ture
Hausmannite
Tetragonal
Metallic
Black
C— Acute pyramidal, cyc-
Greasy
Brownish
Mn,MnO.
hc twins not uncom-
Opaque
black
M — Granular, compact
Monoclinic
Submetallic
Brownish
C— Long fibrous, bladed,
Resinous
black
stalky; often diver-
Translucent
Black
gent, without good
to opaque
terminations
H — Compact, lamellar.
granular
Uaoomman color.
ijGoogle
1. Dark Gray Or Black Ih Color
Cleavage - Fracture - Tenacitjr
Specific
Gravity
Light orange Dark brown
C— Priamatic, not
conspicuous F— Conchoidal Brittle
Yellow Yellowish browi
n perfect
F— Uneven, splintery Brittle
While Gn,y
C— Prismatic F— Conchoidal Brittle
Dark brown to black thorite
sometimes contains nucleus of OTongite, yellow to orange in color. Thorite believed to be deeompoBed oraugite.
Usually with other iron ores; in cavities in hematite or limonite. Crystals and cleavage distinguish it from limonite.
Generally in crystals. With feld- spars, pyroxenes, amphibolea, chlorite, scapolite, zircon, apatite.
F — Conchoidal,
splintery Brittle
Often with black varnish-like sui face, passing into the soft, yellow earthy or ocherous variety. With pyrite, hematite, magnetite, goethite, siderite. Pseudo- morphs after pyrite verycf
s.
Chestnut brown
C— Basal, perfect
Steep, horizontally striated, octa-
F— Uneven Brittle
hedral-like bipyramids and com- plex twins. With manganese minerals— pyrolusite, psilome-
hematite.
Yellowish brown
Structure, cleavage, and specific
Greenish gray
perfect, conspicu- Brittle
7,3
gravity important. Compare wolframite. In quartz veins,
galena, tetrahedrite.
.jGoogle
A. Hhierals With Hetallic Luster
Streak— Vbite, gray, green, red, brown, or yellow
Name, Composition, and
References
Cryatallization Structure Crystals -C Massive— M
Luster Transparency'
Wolframite
Monodinic Submetallic Dark gray
C — Tbick tabular, short Metallic Brownish
columnar, often Opaque black
Moeea laie Iron black
Dana, Pareooa M — -Bladed, curved 1am-
639, 235 ellar, granular
HORKBLERDE (Amphibole)
Monoclinic Sub metallic
C — Long prismatic, prism Vitreous
Silicate of Ca, Mg, Fe, Al, etc. angle 124°; often Opaque to
with rhombohedraU translucent
like terminations M — Bladed, fibrous,
253, 399. 389 granular, compact
Pitch black
Greenish
Adgite
Monoclinic
Submetallic
Pitch black
C — Short prismatic,
Vitreous
Greenish black
Silicate of Ca, Mg,
Fe, Al,
thick columnar,
Opaque to
Browoish
etc.
prism angle 87° M— Compact, granular,
black
m
245, 390
3S6
S
Orthorhombic
Metalloidal
Black
£
C— Prismatic, tabular.
Pearly
Brownish
(Fe,Mg),(SiO,),
rare
Opaque to
black
M— Granular, foliated.
translucent
Greenish black
cleavable aggre-
242, 386
gates
PulomeUne
Amorphous ?
MetalUc
Iron black
M— Botryoidal, reni-
Dull
Bluish black
MnO„ BaO, H,0, etc.
form, stalactitic;
Opaque
Dark gray
129. 362.
smooth surfaces
Ilmenite (Menaccanite)
Heiagonal
Metallic
Iron black
C— Thick tabular.
Brownish
FeTiO,
rhombobedral M — Thin plates, granu- lar, compact; dis- seminated grains;
Opaque
black
239. 336.
pebbles or sand
ijGoogle
1. Daic£ Gray Or Black Ot Color
Cleavage — C
Fracture -F Tenacity
C— Clinopinacoidal,
perfect, conspicu-
DistinguiBhed from hueberuite by streak. Powder may be slightly magnetic. With cassitrite, quartz, mica, fluorite, apatite, 8cheelit, molybdenite, huebner- ite.
Gray C — Prismatic, perfect,
Grayiali green conspicuouB124''
Grayish brown Brittle YeUow
Simple, pseudo hexagonal crystale and cleavages at 56° and 124° important. Very common and in nearly all types of rocks. With calcite, feldspars, quartz, pyroxenes, chlorite.
Grayish green
C— Prismatic, per-
Crystals usually eight-sided, more
Gray
fect, conspicuous —87° Brittle
rarely tour-aided. Pseudotetrag- onal, with prism angles of 87° and 93°. Cleavage less distinct than on hornblende. Common in basic eruptive rocks and crys- taUine hmestones.
White
C — Brachypinacoida 1,
Copper red iridescence often noted.
Grayish
perfect, conspicu- ous
F— Uneven
Brittle
due to small tabular inclusions.
igneous rocks; with feldspar (lab- radorite), olivine, hornblende, pyrrhotite, magnetite.
Dark brown
F— Conchoidal, un-
3,7
Often with fine sooty coating of
Blackish brown
even Brittle
nese minerals; limonite, barite.
Dark brown
C — None, partings
Often slightly magnetic. With
Reddish brown
may be noted F— Conchoidal Brittle
hematite, magnetite, apatite, serpentine, titanite, rutiie. Com- mon in black sands.
L.onz=cB>
A. Bcoierals With Hetaluc Luster
Streak — White, gray, green, red, brown, or yellow
Cryatallization
Structure Luster
Crystals — C Transparency
Massive— M
Samahskite
Orthorhombic
Sub metallic
Velvet black
C— Rare
Greasy
Black
R,"R,"'(Nb,Ta),0„
M-Compact, apparent-
Opaque
R" -Fe, Ca, U0„ etc.
ly amorphous; dis-
R"'=.Ce, Y, etc.
M™
seminated grains
Kraus, Dana,
ParaoD,
168. 492,
Chromite
Cubic
Submetallic
Iron black
Pitchy
Brownish
(Fe.Cr) [(Cr,Fe)OJ,
M — Compact, granular.
Opaque
black
158. 341.
Orthite (Allanite)
Black
C— Tabular, rare
Greasy
Pitch black
Ca,(Al,Ce,Fe),(Al,OH)<SiO,),
H — Compact, granular,
Opaque to
Brownish
bladed, disseminated
translucent
black
grains
201. 440,
Anatase (Octahedrite)
Tetragonal
Metallic
Only in crystals, — py-
Adamantine
Brownish
TiO,
ramidal, tabular;
Opaque to
black
re, 346,
rarely prismatic
translucent
Reddish black
Brookite
Orthorhombic
MetaUic
Iron black
Only in crystals, —py-
Adaraautine
Reddish black
TiO,
ramidal (often with hexagonal habit).
Opaque
Brownish
black
76, 347,
prismatic, tabular
Perovskite
Pseud ocubie
Metallic
C — Apparently cubes,
Adamantine
Grayish black
CaTiO,
ten striated M — Reniform aggregates.
Opaque
Brownish black
238, 487,
rounded grains Hexagonal
HEMATITE, varieties
MetaUic
Iron black
Specular iro
n ore
C— Pyramidal, tabular.
Dull
Reddish black
Fe,0, Compact
rhombohedral
Opaque
Dark steel gray
MaHUe
H — Compact, granular,
ArgiOaceom
micaceous, columnar, radiated reniform or botryoidal
88, 334,
ijGooglc
Reddiah bro? Yellowish brown
L DABE GRAY OR BLACK IV COLOR HanliuBB 3 to 6
Cleavage — C Fracture -F Tenacity
F— Conchoidal,
Specific
Gravity
Splendent luster, conchoidal frac- ture, and apparently amorphous structure important. With columbite, feldspars.
6.6 Dark brown Grayish brown
6.5 Grayish 6. Brownish gray Pale brown
C — Octahedral, indis-
F — Uneven, conchoid- al Brittle
C— Pinacoidal, indis-
F— Uneven, conchoid- al Brittle
May be slightly magaetjo. Pitch- like appearance. With serpen- tine, chrome garnets, zaratite; also in black eands and platinum placers.
Often coated with yellowish or brownish alteration product. Disseminated in the more acid igneous rocks; also in hmes tones. With magnetite, epidote, quartz, feldspars.
B.D
Gray
C— Pyramidal, basal,
Crystals often resemble elongated
White
perfect F— Subconchoidfll
octahedrons. With brookite, rutile, ilmenite, adularia, titanite.
Brittle
gold.
Pale yellowish
C— Indistinct
Crystals may be deeply striated.
brov/n
F— Uneven
Not twinned like rutile. With
Gray
Brittle
rutile, anatase, titanite, ilmenite, adularia, nephelite.
White
C— Cubical, fairly dis-
With chlorite, magnetite, lime-
Grayish
tinct F— Uneven
Brittle
6.D
Cherry red
C— None, parting
4,9
Specular iron ore, crystals or
Reddish brown
F— Uneven Brittle
sparkling scales and grains, often with iridescent tarnish; compact hematite, fibrous, columnar, reni-
form; martite, octahedral crys- tals, pseud omorphous after mag- netite; argillaceoua hematite, impure from sand, clay, jasper.
A. Minerals With Metallic Lusier
Streak— White, gray, green, rpd, brown, or yellow
Crystallization Structure Cryatala— C Massive— M
Luster
Transparency
Framklihite
{Fe,Mn,Zn)(FeO.)
Kiaus. 158,
DSBfl.
341,
Cubic
C— Octahedrons, alone or
with dodecahedron; often with rounded MoMa edges PoQfl M — Compact, granular, 217 rounded grains
Metallic
Dull Opaque
Iron black
FeR<]U80NITE
YCNb,Ta)0.
Tetragonal
C— Pyramidal, rare
Vitreous Dull
black
Translucent opaque
Streak — White, gray, green, red, brown, or yellow
HEHATriE, varieties
Specular ire Fe,Oi Compact
Martite ArgilUuxout
Hexagonal Metallic
C — Pyraroidal, tabular. Dull
rhombohedral Opaque M — Compact, granular,
radiated reniform or botryoidal
Iron black Reddish black Dark steel gray
FRASELIinTE
Cubic
Metallic
Iron black
C— Octahedrons, alone
Dull
(Fe,Mn,Zn){FeO,),
dron; often with rounded edges M — Compact, granular,
Opaque
16S. 341,
17 rounded grains
COLDMBITE (TantaUte)
Orthorhombic
Submetallie
Iron black
C — Stort prismatic, tab-
Greasy
Brownish
(Fe,Mu)[(Nb,Ta)OJ,
ular
Dull
black
M— Compact, dissemi-
Opaque
nated
169, 490.
Tetragonal Metallic Iron black
C — PriBmatic, vertically Adamantine Brownish
striated; twinned. Opaque to black
yielding knee-aped translucent Reddish black or rosette forms M — Compact, dissemi-
zjccyGoole
1. DAR£ GRAY OR BLACK m COLOR
Hoidnesa 3 to 6
Cleavage
Fracture -F Tenacity
Gravity
C — Octahedral, indis-
F— Conchoidal Brittle
Powder frequently alightly mag- netic. Diatinguihed by agaoci- ates— wiUemite (yellow to green), xincite (red), rhodonite (flesh red), calcite.
6.G Pale brown 6. Dirty brown
F — Conchoidal,
Luster on fresh fracture submetal- lic, otherwise dull. Less com- mon than columbite. With quartz, lircon, gadolintte.
Reddish brown C — Octahedral, Dark brown tinct
F— <;onchoidal
Brittle
Specular iron ore, crystals or sparkling scales and grains, often with iridescent tarnish; compact hematite, fibrous, columnar, reni- form; martite, octahedral crystals, pseudomorphous after magnetite; aTgillaceoua hematite, Impure from sand, clay, jasper.
Powder freguently sUghtly mag- netic. Distinguished by associ- ates — wiUemite (yellow to green), lincite (red), rhodonite (flesh red), calcite.
6. Reddish brown C — Pinacoidal, n 6.5 Blackish brown conspicuous
F— Conchoidal, u
Brittle
Pale yellowish C — Prismatic, brown ramidal, n
Gray spicuous
F — Uneven Brittle
Fracture surface i descent. With beryl, tourma- line, spodumene, cryolite. Tan- talum predominates in tantalite, and specific gravity may be as high as 9.
Not as heavy aa casaiterite. Sometimes in fine hair-like in- clusions. Widely distributed. With quartz, feldspar, hematite, ilmenite, chlorite, brookite, apa- tite.
zjcCyGoOgIC
A. Hinerals With Metallic Luster
Streak— White, gray, green, red, brown, or yellow
CrystalUaation
Name, Composition, and
Structure
Luster
Reterencea
Crystals -C Mave=M
T an pa n y
Gadolinite
Subm talU
Black
C— Priamatic, rough, rare
T an 1 nt
Greenish
Fe[Be(Y.O)SiOJ,
M — Compact, disBemi-
black
nated
Kreug, Dana, Piiraoiu
193. 438.
CASSriERITE, varieties
Tetragonal
BUck
Ordinary
C— Thick prismatic.
Dull
Brownish
SnO, or SnSnOj Stream ttn
knee-shaped twins,
M — Compact, reniform, botryoidal, rounded
to opaque
black
80. 344. 249
pebbles
Cubic
GARRET, varieties
Submetallic
Velvet black
Aftdradite
Brownish
R,"R,"'{SiO. Atmandile
tragonal trisoctahe-
to opaque
black
B" -C8,Fe,Mg
drons, alone or in
R"' -Al,Fe
combination, com-
M — Granular, compact, lamellar, dissemi-
208. 41fi. 39
nated; sand
Tourmalihe
Hexagonal
Submetallic
Pitch black
C— Prismatic, vertically
Pitchy
Brownish
M,'Al,{B,OH)i.Ox,
striated, terminated
black
M' NB,K,Li,Mg,Fe
with broken or
surfaces
M— Compact, divergent columnar, dissemi-
Bluish black
193. 447. 409
nated
CORDHDUM, variety
Hexagonal
Metallic
Dark gray
Emery
M— Fine to coarse gran-
Dull
Black
AI,0, with Fe.O., Fe,0„ 810,
ular
Opaque
1. Dark Gray Or Black In Color
Hardness otot 9
Cleavage Fracture -F Tenacity
Characteristics and Aeaociates
Greenish gray C — None
F--Conchoidal, splin- tery Brittle
4.5 In granitic rocks and pegmatites, with fergusonite, orthite, fluorite, molybdenite.
Pale brown Pale yellow White F— Uneven
Brittle
-Prismatic, imper-
C — Dodecahed ra I ,
distinct F — Conchoidal, un
Distinguished by high specific gravity and hardness. In veins cutting granite, gneiss; also in alluvial deposits, aa stream tin. With quartz, wolframite, scheel- ite, arsenopyrite, molybdenite, tourmaline, fluorite, apatite.
Andradite, commonly with magne- tite, epidote, feldspars, nephelite, leucite; almandile, with mica, stauTolite, andalusite, cyanite, tourmaline.
White Gray
Spherical triangular crosa-Bection and hemimorphic development important. In pegmatites; meta- morphic rocks; alluvial deposits. With quartz, feldspar, cassiterite, beryl, topas, fluorite.
Yellowish C — Indistinct
brown F — Uneven
Blackish brown Brittle to tough
Corundum mixed with magnetite, hematite, quartz. Resembles iron ore, powder may be mag- netic. Properties vary with composition. With mica, amphi- boles, chlorite, spinel; in crystal- line limestones, schists, perido- tite.
jyGoogIc
A. HnTERALS WITH HETALUC LUSTER Streak — White, grayi green, red, brown, or yellow
Name, Compoeition, and References
CrTstalliiation
Structure CrystalB-C Massive— M
LuBter
Transparency
£IIIEL, varieties
PleonaaU
R."Cr"'0,),
HercyniU
R"-Mg,Fe
Gahniie
Zn,Mn
PieolUe
R"'-A1, Fe
DystuUe
Knuu, Duia, Panoiu
Cubic Submetallic Blaek
C— Octahedral, well de- Dull Browniab
veloped, common Nearly opaque black H — Compact, granular, Greenish
diBBeminated grains; black
Streak— Black
Hexagonal Metallic Bluieh lead
C — Tabular, rare Opaque gray
M — Disseminated grains, scales, foliated
2Ss.
GRAPHrrE (Plumbago, black Hexagonal Metallic
lead) C— Tabular, rare Dull
C MFoliated, scaly, gran- Opaque
ular, earthy
Sos
Pyrolustte
Orthorhombic ?
Metallic
Iron black
C— Often pseudo-
Dull
Dark steel gray
MnO,
morphous after man- ganite M— Columnar, fibrous, acicular, often di- vergent; dendritic;
Opaque
M7,
powdery
Pitchy
Asphalt (Mineral pitch)
Amorphous
Black
Solid, or thick liquid
Brownish
C, H, 0, etc.
Dull
black
289,
Ms,
Opaque
ijGoogle
1. DARK GRAT OR BLACK Of COLOR
Hardness over 6
Cleavage — C Fracture -F Tenacity
Specific Gravity
Characteriatica and Associates
Grayiah Grayish green Pale brown White
C — Octahedral, indis-
F — ConchoidaL Brittle
CommoD. contact mineral in granu' lar limestones; in igneous rocka, especially the more basic olivine- bearing types ; also rounded grains in placera. With calcite, chondrodite, serpentine, brucite, . olivine, corundum, graphite, P3Toxene8.
glazed porce- lain (graphite, shiny black)
C — Basal, perfect Sec tile, lamellie ai flexible
Marks paper. Soft and greasy like graphite, but heavier and lighter colored. In granite with cassiterite, wolframite; also in crystalline limeatone.
Black, shiny C — Basal, perfect
Dark silver gray Sectile, lamellse ai flexible
Greasy feel; marks paper; darker than molybdenite and not a a heavy. In crystalline limestone with garnet, spinel, pyroxenes, amphiboles; also in shale, gneiss, and mica schist.
Often soils fingers. Darker than Btibnite. With psilomelane, manganite, hematite, limonite.
Characteristic odor when plastic. May be sticky. Independent deposits and impregnations in sand, shale, sandstone, limestone.
:y
A. Hdierals With Metallic Luster
Streak— Black
Ciyetallisation
Structure Luster
Crystals — C Transparency
Massive
Wad MnOj, H,0, etc.
Amorphous ? Dull Brownish
H — Elarthy, Bometimes Submetallic black
with globular struc- Opaque Black
Melaconite (Tenorite) CuO
Bituminous Coal (Soft c C, H, O, etc.
Metallic
C — Thin, scaly, pseudo- Dull
hexagonal (tenorite) Opaque M — Earthy, sooty (melac- onite)
Amorphous Pitchy
M — Compact; may show Vitreoua
strati lication; lamel- Dull
lar, rarely fibrous Opaque
Black
Brownish black
Anthracite Coal (Hard co
al)
Amorphous
Submetallic
Iron black
H— Compact
Vitreoua
Black
C, principally
Opaque
292, 546
3e9
Stibnite
Orthorhombic
Metallic
Dark lead gra
C— Prismatic,
bent.
Opaque
Black
twisted, c M— Fibrous,
Waded,
30, 233
columnar,
granular
Orthorhombic
Metallic
Dark lead i
C — Acicular, long
Opaque
Steel gray
M— Fibrous, hair-like and felted, compact
88, 308,
Polybasite
Monoclinic
Metallic
Iron black
C— Tabular, six-sided.
Opaque
(Ag,Cu)bS.
with beveled edges M— Compact, dissemi-
301 nated
Stepbanite (Brittle silver o
e) Orthorhombic
Metallic
Dark lead g
C— Tabular, thick pris-
Opaque
Iron black
Ag..Sb.
matic H — Compact, diasemi-
300 nated
ijGooglc
1. Dark Gray Or Black Hi Color
Hardness I to 3
Cleavage -C Fracture "F Tenacity
Specific
Gravity
2. Grayisb black
C — Uneven F— Earthy
Crystals, brittle
F — Cubical, conchoi
F— Conchoidal, con- spicuous Very brittle
C — Brachypinacoida 1,
perfect, conspicu- ous, jaelding long, shiny faces
Slightly Bcctile
C— Basal, rather con- spicuous
F — Uneven
Brittle
spicuous F — Uneven Brittle
C — Imperfect F — Uneven Brittle
Soft varieties soil fingers. Appar- ently very light and floats on water, due to porosity. Usually adheres to tongue. With psilom- elane, pyrolusite, s i d e r i t e , limonite.
Coatings or crusts on copper min- erals, especially native copper, chalcopyrite, bornite, chryso- coUa. Earthy varieties soil fing er
Distinguished from other coals by conspicuous cubical fracture. Sometimes shows iridescence and distinct plant remains. With slate, psTite, marcasite.
Conchoidal fracture, luster, and absence of plant structure impor- tant. Often iridescent. With slate, pyrite, marcasite.
Tarnishes black, sometimes iri- descent. In veins with quarts, sphalerite, galena, cinnabar, barite, gold.
Felted, fibrous masses often with feathery appearance. Heavier than Btibnite and cleavage trans- verse to length. Sometimes with yellow coating. With bournonite, galena, sphalerite.
Best known in crystals. Thin splinters are cherry red in trans- mitted light. With other silver minerals — stephanite, argentite, pyrargyrite.
More brittle than argentite. In veins with other silver minerals; also barite, galena.
:y
A. UniERALS WITH METALLIC LUSTER
Streak— Black
Refereocee
CrystalliEation Structure Crystals -C Massive -M
Luster
Color
Aientite (Silver gia
Kmue, 48,
Qce)
Duns, 2SS.
2B7
Cubic
C— Octahedral, cubical,
often distorted H — Compact, arbores- cent; coatings
MetaUic Opaque
Dark lead gray Black
GALEHA (Galenite) PbS
287,
Cubic
C—Cubea alone, or
well developed com- mon M— Granular, cleavable aggregates, compact
Metallic Opaque
Dark lead gray
Chalcocite
49,
Orthorhombie
agonal, deeply striated M— Granular, compact, disseminated
MetalUc Opaque
Dark lead gray, often tar- nished dull black, blue, or green
Boumonite (Cog-wheel ore
Orthorhombie C— Thick tabular; cog- wheel twins H— Compact, granular
Metallic Opaque
Dark steel gray Iron black
Stromeyerite
(Cu,Ae)
29S
Orthorhombie CTabular, rare M— Compact
Metallic Opaque
Dark lead gray
Enargite
Cu.AbS.
Orthorhombie C— Prismatic, small, rare H — Compact, granular, columnar
MetalUc
Submetallic
Opaque
Grayish black Iron black
Streak— Black
Tetrahedrite
312,
Cubic
C— Tetrahedral, often
MGranular, compact
Metallic Opaque
Dark steel
gray Iron black
ijGoogle
I. DARK ORAT OR BLACK in COLOR.
Cleavage — C Fracture -P Tenacity
Specific Gravity
Characteristics and
Dark lead gray, C— Indistinct shiny F— Hackly
Perfectly aectile
Grayish black Dark lead gray
C — Cubic, perfect,
Cuts and takes impression like lead, hence easily distinguished from other soft, black minerals. With silver, cobalt, nickel ores- prouBtite, pyrargyrite, smaltite, niecolite.
Characterised by cleavage and high specific gravity. Changes to cerussite or anglesite. With sphalerite, p3vite, chalcopyrite, calcite, fluorite, barite.
2.B Dark gray, shiny C — Indistinct
3. Black, shiny F — Conchoidal
Rather brittle
Moru brittle than argentite. Often coated with malachite (green), azurite (blue). With chalcopyrite, bomite, tetrahe- drite, galena.
Dark gray
C— Imperfect
Easily recognized by cross or cog-
Black
F— Uneven Brittle
wheel appearance. With galena, sphalerite, tetrahedrite, siderite.
Dark lead gray
C— Indistinct
stibnite, chalcocite.
a. 2
Resembles chalcocite but not as
Black
F— Conchoidal Slightly aectile
abundant. With copper and chalcocite, tetrahedrite.
3. Grayish black
C — Prismatic, perfect, often conspicuous F — Uneven Brittle
In artificial light usually resembles sphalerite. In veins with other copper minerals— chalcopyrite, bomite, chalcocite, tenantite, famatinite.
Dark gray Black
C — Indistinct F — Uneven Brittle
Characteristic crystals, sometimee coated with chalcopyrite. With sphalerite, galena, boumonite, siderite, malachite.
:y
A. Miherals With Metallic Luster
Streak— Black
Cryatalluation
Structure Crystals -C Massive— M
Luster Transparency
Hexagonal ' Metallic Dark gray to
C — Rare Opaque black on ex-
M — Compact, scaly, fine posure, tin
1 granular, with reni- white on
a form or botryoidal fresh frae-
structure ture
DranlDite (Pitchblende) -
Cubic
Pitch-like -
Pitch black
C— Octahedral, rare
Submetallic
-Brownish
UO., U0„ PbO, etc.
M— Botryoidal, colum-
Du.l
black
nar, curved lamellar
Opaque
Greenish
granular, compact.
black
apparently amor
142. 521,
phous
Tetragonal Metallic
C— Small, rare Opaque
H — Compact, granular ' disseminated
Iron (Native iron)
Cubic
Metallic
Iron gray
C— Rare
Opaque
Black
Fe
M — Disseminated grains, scales, lumps
18,
Wolframite
Monoclinic
Dark gray
C— Thick, tabular, short
Metallic
Brownish
(Fe, Mn)WO.
M— Bladed, curved lamellar, granular.
Opaque
black Iron black
141,
compact
Psilomelane
Amorphous?
Metallic
Iron black
H— Botryoidal, rem-
Dull
Bluish black
MnO„ BaO, H,0
etc.
form, etalactitic;
Opaque
Dark gray
]29.
smooth surface
Ilmenite (Menaccanite)
Hexagonal
Metallic
Iron black
C— Thick tabular, rhom-
Submetallic
Brownish
FeTiO.
bohedral M— Thin plates, granular, compact, dissemi- nated grains, peb-
Opaque
black
239,
-Sm.
bles, sand
ijGooglc
DAS£ GRAY OR BLACK IN COLOR Hardness over 3
Cleavage C Fracture -F
Tenacity
Characteristics and
C — Basal, not conspic-
Often breaks onion-like layers. Color streaks darken on exposure. With silver, cobalt, nickel ores — proustite, smaltite, chloanthite.
3. Brownish black F — Conchoidal, 6,5 Grayish black uneven
Pitch-like appearance and fracture important. Fresh material is hard and heavy. With ores of lead, silver, bismuth; thorite, orthite, fergusonite.
C — Indistinct F — Uneven
Brittle
Often yellowish from admixture ofchalcopyrite. Withcassiterite, wolframite; in tin ore deposits.
4.B Iron gray, shiny C — Cubical, i 6. spicuous
F— Hackly
Malleable
6. Brownish black C— Clinopinacoidal, S.G Black perfect, conspicuous
F — Uneven
Brittle
Black F— Conchoidal,
Brownish black even
Brittle
Alloyed with more or less nickel. Strongly magnetic. In mete- orites or basic igneous rocks (basalts). With troilite, pyrrho- tite, olivine, graphite.
Structure, cleavage, and specific gravity important. Powder may be slightly magnetic. With eas- siterite, quartz, mica, fluorite, apatite, scheelite, molybdenite, huebnerite.
Often with fine, sooty coating of pyrolusite. With other manga- nese minerals; limonite, barite.
Black C — None, partings
Brownish black may be noted
F — Conchoidal
Brittle
Sometimes slightly magnetic but not as strongly as magnetite. With hematite, magnetite, apatite, serpentine, titanite, ru- tile. Common in black sand.
:yG00glc
A. HnrERALS WITH UETALLIC LUSTER
Streak—
Crystallization
Name, Oompodtion, and
Structure
Luster
Crystals -C Maaeive-M
Transparency
Ilvaile
Orlhorhombie
Submetallic
Black
C — Columnar, acicular.
Opaque
Greenish
CaFe,(Fe.OH)(8iO.),
vertically striated
black
Mwk
H— Compact with radial
Brownish
Psraow
fibrous structure.
black
196. 445,
granular
Maghetite
Cubic
COctahedrons, dodeca-
Metallic
Iron black
Pe(FeO,),
hedrons, common M— Compact, granular, lamellar, diBsemi- nated, sand
DuU Opaque
ISe. 33S.
FRASKLiniTE
Cubic
C— Octahedrons, alone or
MetaUic
Dull
Opaque
Iron black
(Fe,Mn,Zn){FeO,),
edges often rounded H — Compact, granular.
158, 341,
Braunite
Tetragonal
Metallic
Black
CApparently octahe-
Greasy
Dark brown-
MnMnO,
drons, small H — Drusy crusts, granu-
Opaque
ish black
128. 343.
22S
lar aggregates
COLUHBITE (Tantalite)
Orthorhombic
Submetallic
Iron black
C — Short prismatic, tab-
Greasy
Brownish
ular
DuU
black
(Fe.Mn)[(Nb,Ta)OJ,
H— Compact, disaemi- nated
Opaque
lao. 490,
CORDHDUM, variety
Hexagonal
Metallic
Dark gray
Emery
Always massive, fine to
DuU
Black
A1,0„ with Fe,0., Fe,0
SiO,
coarse granular
Opaque
ijGoogle
1. DAHK GRAY OR BLACK HT COLOR Batdnu over 3
Cleavage — C Fracture — F Tenacity
Specific Gravity
5.S Black C— Finacoidal
6. Brownish black F — Uneven
Greenish black Brittle
Often covered with yellowigh alteration product which reduces hardness. With dolomite, pyrox-
C — Indistinct, octa- hedral parting
F— Conchoidal, un- even
nrittle
Black C — Octahedral, indie-
Brownish black tinct
F — Conchoidal
Brittle
Very strongly magnetic. Crystals usually perfect and with bright surfaces. Independent deposits; djeeeminated; black Bands. With chlorite, hornblende, pyr o:(ene, feldspar, quarti, pyrite, chalcopyrite.
Powder frequently slightly mag- netic. Distinguished by associ- ates — willemite (yellow or green), lincite (red), rhodonite (flesh red), calcite.
6. Black C— Pyramidal
6.6 Brownish black F — Uneven Brittle
4 . 7 Small, untwinned octahedral crys-
4.9 tals. With manganese minerals
— pyrolusite, psilomelane, haus-
mannite; magnetite, barite, hema-
C — Pinaooidal, not
6.6 Brownish black Grayish black
Fracture surface sometimes irides- cent. With beryl, tourmaline, spodumene, cryolite. Tantalum predominates in larUaliie and specific gravity may be as high
Black Brownish black
C — Indistinct F— Uneven Brittle to tough
Corundum mixed with magnetite, hematite, quartz. Resembles iron ore and powder may be mag- netic. Properties vary with com- position. With mica, am phi- boles, chlorite, spinel; in crystal- line limestone, schist, peridotite.
jyGoogle
UniERALS WITH METALLIC LUSTER Streak— Metallic wbite or steel gray
CryBtallizatioi Structure Crystals Massive — M
LuBter
Transparency
Blercury (Quicksilver)
Cubic, at— 39° C, liquid Metallic at ordinary tempera- Opaque
Sylvanite
(Au,Ag)Te
MonocUnic
C— Rare
M— Branching arbores- cent forms, simulat- ing written charac- ters; bladed, colum- nar, granular
MetalUc Opaque
Silver white Steel gray, at times with brassy tinge
Bismuth
Bi
Hexagonal C— Rare
M— Reticulated, arbo- rescent, platy
Metallic Opaque
Silver white, with reddish tinge
Silver
Ag
Cubic
C— Small, often distorted M— Grains, scales, plates, twisted hair- or wire- like forms, lumps
Metallic
Opaque
Silver white, tarnishing yellow, brown, or black
gray
Amalgam (Si
(Ag,Hg)
24, 279.
Cubic C— Rare
M— Plates, coatings, em- bedded grains
Metallic Opaque
Silver white
Antimony
Sb
Hexagonal C— Rare
M — Compact, granular, lamellar
Metallic
Opaque
Tin white
Light steel gray
Djwcrasite
48. 2Sfl.
Ortho rhombic
C— Columnar, tabular,
M — Compact, granular, nodular, coatings
Metallic Opaque
Silver white, tarnishes yellow or black
ijGooglc
2. Metallic White Or Light Bietallic Gray Ht Color.
Hardneas 1 to 3
Cleavage — C Fracture -F
Tenacity
C — Clinopinacoidal , perfect, usuallij' conspicuous
F — Uneven
Brittle
ResembleB ancient script, hence graphic tellurijim. With gold, cakverite, aphaierite, pyrite, tetrahedrite.
2. Lead gray, shiny C — Basal, perfect, usu- 3.6 ally conspicuous
Sectile
2.S Silver white, C — None
3. shiny F — Hackly Light lead gray, Malleable, ductile
Often shows brassy tarnish colors. With silver, cobalt, nickel, tin ores — smaltite, niccolite, chloan- thite, cassitrit; wolframite.
Color and streak darken on expo- sure. With silver, lead, araenic, cobalt, nickel ores — argentite, pyrargyrite, proustite, smaltite, galena; fluorite, calcite, barite.
Hardness over 3
C— None 13.7
F— Conohoidal 14,1
Brittle to malleable
With native mercury, cinnabar, and silver minerals.
Tin white Lead gray
C — Basal, perfect, usu
ally conspicuous F— Uneven
Brittle
C— Domatic F — Uneven Sectile
Does not tarnish readily. With silver, arsenic, and other anti- mony minerals — kermeaite, stib- nite, smaltite, allemontite. Sometimes coated with white oxide of antimony.
:yGoogle
A. milERALS WITH METALUC LUSTER
Streak— Hetallic white o
r steel gray
Name, Compoaitioii References
,aiid
CrystaUization Structure Crystaia -C MaBBive=M
LuBter Transparency
Color
Platinum
Cubic
C— Small, rare
Metallic
Opaque
Tin white
Steel gray
Iridoshium
COa,Ir)
Hexagonal
Metallic
Tin white
CThin tabular
Opaque
Light steel
M— Scales, flattened
gray
p-ains
Streak— Black
Blolybdenite MoS,
Hexagonal
C— Tabular, rare H— Disseminated grains, scales, foliated
MeUllic
Opaque
Bluish lead gray
B18Mutkinitb
Orthorhombic
C — Acicular, rare M— Granular, foliated, fibrous
Metallic
Opaque
Lead gray Tin white
Stibhtte
30,
Orthorhombic
C— Prismatic, bent, twisted, common
M— Fibrous, bladed, co- lumnar, granular, compact
Metallic
Light lead gray
Jambsonitb
Orthorhombic
C — Long, acicular M— Fibrous, hair-like, felted, compact
Metallic
Opaque
Steel gray Lead gray
GALEHA (Galenite) PbS
Cubic
C— Cubes, alone or with
octahedron, common,
well developed M— Granular, cleavable
Metallic Opaque
Lead gray
287,
aggregates
ijGoogle
Hetaujc White Or Light Metallic Gray Ih Color. 43
HardneBS more than 3
Cleavage —C Fracture
Tenacity
I Specific
Light Bteel gray, C — None shiny F — Hackly
Malleable, ductile
C — Baaal, perfect F — Uneven Slightly malleable
Heavier than silver and does not tamiah. May be magnetic if much iron be present. With chromite, magnetite, gold, iri- doanuum.
Distinguished from platim greater hardness. In place with platinum, gold, chromite
by
Hardness 1 to 3
Dark lead gray, C— Basal, perfect greenish on SecUle, lamelte fle:(ible glazed porce- lain (graphite, shiny black)
C — Brachypinacoidal, perfect, rather con- spicuous
Slightly sectile
C — Brachypinacoidal, perfect, conspicu- ous, yielding long shiny faces
Slightly sectile
Marks paper. Soft and greasy like graphite but heavier and lighter colored. In granite with cassitente, wolframite; in crystal- line limestone. Heavier and lighter in color than stibnite. With cassiterite, bis- muth, chalcopyrite, gersdorffite, wolframite- Differs from galena in cleavage and specific gravity. TamiaheH black, sometimes iridescent. In veins with quartz, sphalerite, galena, cinnabar, barite, gold.
Grayish black CBasal, rather con- spicuous F — Uneven Brittle
Dark lead gray C — Cubic, perfect, very Grayish black conspicuous
Brittle
Felted fibrous masses, often with feathery appearance. Heavier than stibnite and cleavage trans- verse. With bournonite, galena, sphalerite.
Characterized by excellent cleav- age and high specific gravity. Changes to cenissite or anglesite. With sphalerite, pyrite, chalcopy- rite, calcite, fluorite, barite.
JyGoOgIc
A. MnrERALS WITH METALLIC LUSTER
Streak— Black
Name, Compoaition, and
References
Cryetallization Structure CryatalBC MaBsive-M
Luster Transparency
Color
Arsenic
As
KraiH, Dmui
uul
Hexagonal
C— Rare
H — Compact, scaly, fine
grained, renitorm,
iwtryoidal
Metallic
Opaque
Metallic Opaque
Tin white, on
ture
Dombtkite
Cu.As
46, 286.
C— Unknown H— Compact, reniform, botryoidal
Tin white, with yellow and
variegated tarnish
L5Llinoite
FeAa,
44, 303,
21S
Orthorhombic C— Rare
H — Granular, dissemi- nated, compact
Metallic
Opaque
Silver white Steel gray
Llnnodte
(Ni,Co).
Cubic
C— Octahedral
MGranular, compact
Metallic Opaque
Steel gray, at times with reddish tinge
Cobaltite
CoAsS
Cubic
C — Cubes, pyritohedrona, small, well developed MGranular, compact
MetaUic Opaque
Silver white Steel gray, at
times with
reddish
tinge
Snultlte
CoAb,
Cubic C— Rare
H — Granular, compact
Metallic Opaque
Tin white
Light steel
gray
Metallic Opaque
Cblouitliite NiAe,
Cubic
C— Rare .
M — Granular, compact
Tin white
Light steel
gray
ijGoogle
2. Metallic White Or Light Bietallic Gray Iit Color
Hardness
iverS
Hard-
Streak
Cleavage -C Fracture -F
Tenacity
Specific Gravity
. Characteristics and
Associates
Lead gray Grayiah black
Grayish black
C— BaBaL,Tiot conapicu
F— Uneven, granular Brittle
Often breaks in concentric or
darken on exposure. With ailver, cobalt, nickel orea—
proustite, smaltite, chloanthite.
S.6
C— None F— Uneven
BritUe
7,5
Tamishes readily and then resem- bles chalcopyrite, but much heavier. With native copper, silver; niccolite, whitneyite.
Grayish black
C — Basal, not conspic-
7,1
Tarnishes gray.
1 arsenopyrite.
Frequently in serpentine. With siderite, cassitrite, arsenopyrite, hornblende.
6.6 Grayish black ' C — Indial
Tarnishes copper red. With chal- copyrite, pyrrhotite, siderite; cobalt and nickel minerals.
C — Cubic, not conspic-
May show red tarnish. Often with pink coating of erythrite (cobalt bloom). With native silver, smaltite, niccolite, pyrrho- tite, chalcopjTite.
S.6 Grayish black
C Indistinct F — Uneven Brittle
May have dull tarnish and pink coating of erythrite. With niccolite, cobalt! t, native bis- muth and silver, proustite, barite, fluorite, calcite.
Tarnishes dull and often coated with green annabergite (nickel bloom). Resembles smaltite but not as abundant. With nicco- lite, cobaltite, proustite, native silver and bismuth, calcite.
ijGoogIc
A. hhierals with metallic luster
Streak— BUck
CryEtallJzation Structure Crystals -C Massive— M
Luster Transparency
Arsehopyrite
Kreus, Dana,
MABCASITE (White i
Orthorhombie
Metallic
Tin white
C— Prismatic, common M — Compact, granular, Mo9 columnar, radial
Opaque
Light steel gray, tar- niahes yel- low
pyrites) Orthorhombie
Metallic
Steel gray
C— Tabular, often
twinned, resernbling cock's combs
Opaque
Pale brass yel- low, more brassy on ex-
H — Compact, atalactitic, 212 globular, radiated
posure
ijGoogle
3. Ketallic White Or Light Metallic Gray Ih Color 47
Hardness more than 3
Cleavage Fracture -F
Tenacity
Gravity j
B.S
Dark grayish
C— Prismatic, not con
Whiter than marcasit. More
black
spicuous F — Uneven Brittle
6,2
common than amaltite or cbloan- thite. With ohalcopyrite, pyrite, sphalerite, cassiterite, amaltite, native gold and silver, serpentine
Dark greenish
C— IndiBtinct
Alters to limonite, melantrite.
black
F— Uneven
Brittle
With other sulphides— galena, sphalerite, chalcopyrite, pyrite;
ijGoogle
A. Miherals With Metallic Ldster
Streak — Gray, brown, or yellow
Ciystallization Structvire
Crystals — C
Luster Transparency
LIHOHITE, varieties
Yelloio ocher Fe,0,(OH). Bog iron ore
— Earthy, porous, clay-like
Earthy
DuH
Opaque
Yellow
Brownish yellow
KrauB, Dana, Psrat
Monoclinic C— Rare H — Compact
Metallic Opaque
C— SmaU,
HGrains, scales, nug- gets, dust
Metallic Opaque
Golden yeHoi Brassy yelloi Light yellow
Sphalerite
Cubic
C— Tetrahedral,
H — Compact, fine or coarse grained, cleav- able aggregates
Adamantine Transparent to
Hexagonal
C — Hemimorphic, rare M— Compact, granular foliated
Vitreous Translucent t opaque
Oraie yelloi Reddish yel-
Orangite (Thorite)
UncomaioB Mior.
Tetragonal Resinous Orange yellow
C — Square prisms with Vitreous Brownish yel-
bipyramids Transparent to low M—Compact, dissemi- translucent
:y
3. YELLOW in COLOR
HardneBs 1 to 6
Cleavage — C Fracture — F
Tenacity ,
Specific Gravity
Yellowish
C— None
brown
F— Earthy
Brittle
Yellow ochcT, earthy, may have greasy feel, when impure gritty; bog iron ore, porous.
C— None F — Uneven
Brittle
With gold, eylvanite, petzite, tet- rahedrite, pyrite.
2.6 Golden yellov
C — None F— Hackly Malleable, ductile
Does not tarnish. Differs from other soft, yellow minerals in atreak, specific gravity, and tenacity. Frequently in quarts veins, placers. With pyrite, galena, sphalerite, areenopyrite, stibnite, chalcopyrite.
i. Orange yellow 4.B Reddish yeUo?
— Dodecahedral, perfect, conspicu-
— Basal, perfect, usually conspicu-
Color and streak vary with im- purities. Extensively in lime- stone. With galena, chalcopy- rite, pyrite, barite, fluorite, sid- erite, rhodochrosite.
Distinguished by associates — cal- cite, franklinite (black), wille- mite (yellow to green), rhodonite (flesh red}. On exposure be- comes coated with the white carbonate.
C — Prismatic, n
conspicuous F — Conchoidal Brittle
Yellow orangite is sometimes sur- rounded by dark brown to black thorite; latter is thought to be decomposed orangite.
:y
A. HmERALS WITH METALLIC LUSTER
Streak— Gray, brown, or yellow
Crystalliiatioi Structure Crystals Massive — U
Transparency
*Goetl]ite Orthorhombic Submetallic YeHow
C — Small, thin tabular, Translucent to Brownish yel- PeO . OH needle-like ; paral- opaque low
leliy grouped or in Mixea scaly, fibrous vel'
Knaa, Dana, raaa vety crusts
63, 349, 220 H — Reniform, stalactitic
Streak— Black
Domeykiti
Cu,As
Hexagonal Metallic
C — Needle-like, radiat- Opaque
ing groups, hair tufts H — Fibrous, compact
CUnknown Metallic
M' — Compact, reniform, Opaque botryoidal
Brass yellow Bronze yelloi
Yellow and variegated
colors on exposure
Chalcopyrite
Tetragonal
Metallic
Opaque
CuFeS,
bling tetrahedrons.
55. 297, 284
M— Compact
Pentlandite
Cubic
Metallio
C— Rare
Opaque
(Fe,Ni)S
K — Compact, granular
35. 293. 238
MARCJITE( White iron pyrites)
Orthorhombic
MetalUc
C— Tabular, often
FeS,
cock's combs M— Compact, stalactitic, globular, radiated
Brass yellow Golden yelloi
:y
3. Yellow Iv Color
HFdDesBllo6
Hard-
nesa
Streak
Cleavage -C Fracture -F Tenacity
Specific Gravity
CharacteriBticB and Associates
6.B
Yellow YeUowish
brown
C— Brachypinacoidal, 4 .
perfect 4.4 F — Uneven, splintery Brittle
Usually with other iron ores; in cavities with hematite or limon- ite.
Dark greenish black
C— Basal
F-Uneven Brittle
Often in cavities in Umeatone or hematite. With pyrrhotite, chalcopyrite, chloanthite, barite, fluorite.
3.6 Grayish black CNone
F — Uneven Brittle
When tarnished resembles chalco- pyrite, but much heavier. Tin white on fresh fracture. With native coppter and silver, nicco- lite, whitneyite. MohawkUe nickeliferous variety.
Greenish black
C— Indistinct F— Uneven Brittle
3.B
Black
C— Octahedral, often
F— Uneven
Brittle
e.
Dark greenish
black Brownish black
C— Indistinct F — Uneven
Brittle
Softer, and deeper yellow in color than pyrite. Frequently with iridescent tarnish. With pyrite, bomite, galena, sphalerite, tetra- hedrite, chalcocite.
Non-magnetic. With chalcopy- rite, pyrrhotite.
Distinguished from pyrite by crys- tallization and lighter color on fresh fracture. Alters more readily than pyrite, forming limonite, melanterite. Occur- rence same as for pyrite, but not as abundant.
JyGoOgIc
A. Hiberals With Metallic Luster
Streak — Black
Name, CompOBition, and References
Crystallization Structure Crystals Massive — M
Luater Transparency
PYRITE (Iron pyrites, fool'H Cubic Metallic Brass yellow
gold) C — Cubes, octahedrons. Opaque Golden yellow
FeS, pyritohedrons, very with varie-
common, often stri- gated tar-
ated nish
Mo8 H — Compact, fine gran- Kraiu. DttDfl, Pareoni ular; botryoidal, stal-
:y
3. YELLOW in COLOR
Cleavage — C
Fracture Tenacity
Chamcteriatics and
GreeniBh black C — Indistinct Brownish black F— Uneven Brittle
Harder than chalcopyrite. Alters to limonite, copiapite. Widely distributed in all types of rocks. With other sulphides — galena, sphalerite, chalcopyrite.
:y
A. UHEIULS WITH METALLIC LUSTER Streak—Oray, red, or ;llow
Crystallisatioi Structure CrysUlfl-C Haesive— H
Luater Transparencjr
Hex&goual Metallic
C — Rare Opaque
H — Reticulated, arbo- Uoeea rescent, platy
Calaverite AuTe,
3oa
C— Rare H-Compact
MetalUc Opaque
Light bronze yellow
COPPER Cu
28,
ZJi.
Cubic
C— Cubes, octahedrons, - tetrabexabedrons
M— Scales, plates, lumps, arborescent aggre- gates
Metallic Opaque
Copper red,
readily red, blue, green, black
Gold
2S4
Cubic
C— Small, distorted, rare M— Grains, scales, dust, DUggets
Metallic Opaque
Golden yellow Brassy yellow Light yeUow
Streak— Black
Cubic
C— Rare
H — Compact, granular
BORHITE Cu,FeS,
5S.
Metallic Opaque
Bronze brown Copper red, on treah frac- ture
HUlerite NiS
Hexagonal
C— Needle-like, often in
radial groups, hair-
tufta H— Fibrous, compact
MetaUic
Brass yellow Bronie yellow
Douetkite
Cu,Aa
C— Unknown
M— Compact, reniform, botryoidal
Metallic Opaque
Yellow
Variegated, on exposure
ijGoogle
4. Brass, Bronze, Or Copper Red Ih Color
Hard-
Streak
Cleavage -C Fracture -F Tenacity
Specific Gravity
Characteristics and
Associates
Lead gray, shiny
C— Baaal, perfect, ubl ally conepicuous
Sectile
Often shows braBsy tarnish. Fre- quently with silver, cobalt,
lite, chloanthite, cassiterite; wol- framite.
Gray
C-None
F— Uneven Brittle
With gold, sylvanite, petzite tetrahedrite, pyrite.
Copper red,
Shiny
C— None F— Hackly Ductile, malleable
Cementing material in conglom- erate or aiing cavities in trap. With cuprite, malachite, azurite, native silver, tenorite, epidote, prehnite, datolite, leolites, quarti, calcite.
Golden yeUow
C-None F— Hackly Malleable, ductile
Does not tamish. Differs from other soft yellow minerals in streak, specific gravity, and tenac-
ity. Frequently in quartz veins; placers. With pyrit, galena, sphalerite, arsenopyrite, stibnite, chalcopyrite.
over 3
Grayish black
F— Uneven Brittle
Usually with peacock tarnish
colors (purple copper ore).
malachit, cassiterite, siderite.
Dark greenish black
C— Basal F— Uneven Brittle
In cavities in limestones, hematite, dolomite. With pyrrhotite, chal- copyrite, chloanthite, barite, fluorite.
3.5 Grajish black
C — None F — Uneven Brittle
When tarnished resembles chal- copyrite but much heavier. Tin white on fresh fracture. With native copper, silver; mccoUt, whitneyite. Mohawkite, niekel- iferous variety.
zjcCyGoOgIc
A. mnERALS WITH METALLIC LUSTER
Streak— Black
CrystalliEation
Structure Crystals -C Massive -M
Name, Composition
,aiMl
I Luster
Color
chalcopyrite;
CuFeS/
Tetragonal
bling tetrahedrons,
MetalUc Opaque
Brass yellow Goldea yellow
Faooa — Compact, granular
Pentlandite
(Fe,Ni)S
Cubic
C— Extremely rare
H— Compact, granular
Metallic Opaque
Light bronze yellow
Pyrrhotite
Hexagonal
C— Tabular, rare
H — Compact, granular
Metallic Opaque
Hexagonal C— Rare
M — Compact, dissemi-
Metallic Opaque
MARCASTTE (White i
Orthorhombic
C Tabular, often
twinned resembling
cock's combs H — Compact, stalactitic,
globular, radiated
Metallic Opaque
Steel gray Pale brass yel-
brassyoi
poBure
PYRITE (Iron pyrites,
tool's gold)
C — Cubes, octahedrons, pyritohedrons, very common, often stri-
H — Compact, line gran- ular; botryoidal, stalactitic
Metallic
Brass yellow Golden yellow, with varie- gated tarnish
:y
4. Brass, Bronze, Or Copper Red Iii Color
Cleavage — C Fracture -F Tenacity
3.S GreeniBh black
C — Indistinct F — Uneven Brittle
Softer, and deeper yellow in color than pyrit. Frequently with iridescent tamiah. With pyrite, bomite, galena, sphalerite, tetra- hedrite, chalcocite.
3.B
Black
C— Octahedral, often
Non-magnetic. With
Chalco-
conepicuouB P-Uneven Brittle
pyrite, pyrrhotite.
C — Basal, not conapic- 4.5 Powder frequently attracted
uous 4,6 by magnet. Subject to dark
P — Uneven brown tamieh. In basic igneoufl
Brittle rocks. With chalcopyrite, pyrite,
pentlandite, galena.
Dark brownish C — Indistinct black F— Uneven
Brittle
Often with green coating of anna- bergite (nickel bloom). With cobalt, nickel, silver minerals — smaltite, prouatite, chloanthite, native silver; native bismuth and
Dark greenish C — Indistinct black F — Uneven
Brittle
Greenish black C — Indistinct Brownish black P— Uneven Brittle
Distiaguished from pyrite by orystalliKBtion and lighter color on fresh fracture. Alters more readily than pyrite, forming limonite, melanterite. Occur- rence same as for pyrite, but not as abundant.
Alters to limonite, copiapite. Widely distributed in all of rocks. With other sulphides — galena, sphalerite, chalcopyrite.
JyGoOgIc
A. MinERALS WITH METALLIC LUSTER
Streak— White, gray, green, red, brown,
Name, Composition, and References
Crystallisation Structure Crystals -C Massive— M
Luater Transparency
Amorphous T Dull Brown
H — Earthy, aometimee SubmetafUc Blackish
MnO„ H,0, etc.
with globular struc-
Opaque
brown
Erwu, Domi, Fanom
ture
130, 362. 231
LIMOHITE, varietiea
C— Unknown
Dull
Yellowish
BTOitm ocher Fe.O.(OH). Bog iron ore Brown elay
M— Compact, earthy, porous, pisolitic, ooUtic
Earthy Opaque
brown Dark brown
iron*tone
Sb, 350. 221
HEMATITE, varieties
Hexagonal
Dull
Brownish
Red other Pe,0, Oolilic
FossUiferova
M— Fine granular, earthy, scaly, oolitic, tossil- iferouB
Earthy Opaque
Cherry red
86. 334. 217
Hexagonal Adamantine Scarlet red
C — Rhombohedral, thick Dull Brownish red
tabular, small, rare Transparent to
M — Fine granular, fi- opaque
brous, diesemihated,
earthy coating
ProuBtite
Hexagonal
Adamantine
Scarlet
C — Small, complex, rare
DuU
Vermilion
Ag.AsS,
bands
Transparent to translucent
Pyrargyrite
Hexagonal
Admantine
Dark red
C-mall, complex, rare
MetalUc
M — Disseminated, crusts.
Transparent to
Sb. 311.
299 bauds
opaque
Copper
Cubic
Metallic
Copper red,
C— Cubes, octahedrons.
Opaque
tarnishing
tetrabexahedrons
readily to
Cu
21, 378.
H— Scales, plates, lumps, arborescent aggre- 282 gates
red, blue, gteen, black
5. RED, BROW, OR BLUE IH COLOR Hardnesa 1 to 3
Cleavage — C Fracture — F Tenacity
C— None
F— Earthy BritUe
C — None
F— Earthy Brittle
Very soft varieticB soil fingers. Apparently very light and floats on water, due to porosity. Usually adheres to tongue. With psilomelane, pyroluute, aiderite, limonite.
Brovm ocher, earthy, may soil fingers; bog iron ore, porous; brown clay irontlone, massive or concretionary, impure from clsy.
Cherry red C— None
Reddish brown F— Earthy Brittle
Red ocher, earthy; oolitic, 1
; fossUiferous, replace' t of Belle.
Scarlet Reddish brown
C— Prismatic, not
FUneven Brittle to sectile
8,2
Color, streak, high specific gravity important; the latter often re- duced by gangue. Disseminated
in aihcious rocks, with native
gar, stibnite.
2.5 Cherry red 3. Purplish red
Copper red,
C— Indistinct F — Conchoidal Brittle
C — Indistinct F — Conchoidal Brittle
C— None F— Hackly
Ductile, malleable
Termed light ruby silver ore. Distinguished from cinnabar by associates. With pyrargyrite, in veins with other silver minerals
galena.
Frequently as gray or dark, red bands, dark ruby silver ore. With proustite, in veins with other silver minerals and galena.
Cementing material in conglomer- ate, or filling cavities in trap. With cuprite, malachite, azurite, native silver, tenorite, epidote, prehnite,datolite, zeolites, quarts, calcite.
zjcCyGoOgIC
A. Miherals With Metallic Luster
Streak— White, gnj, green, red, brown, or yellow
Name, Composition, and References
CrystalliEation Structure Crystals -C Massive— H
Luster Transparency
LIHOniTE, varieties
Compact Fe.O,(0H), Bog iron or. Broum clay ironatOTie
C — -Always pseudo- , Metallic morphs, commonly Dull after pyrite, marea- Opaque site, siderite M — Compact, stalaetitic, botryoidal, nodular; Uoan often with internal
Kram, Dana, Panons radial fibrous struc-
95, 3S0, 221 ture; porous
nnminite (Pitchblende) U0„ U0„ PbO, etc.
Cubic Submetallic
C— Octahedral, rare Dull
H — Botryoidal, colum* Opaque nar, curved lamellar, granular, compact; apparently amor- phous
Yellowish
brown
Dark brown
Blackish brown
HEMATITE, varieties
Fe,0, Compact
Hexagonal Submetallic Brownish red
M — Compact, granular, Dull Dark red
columnar, splintery. Opaque Blackish red
radiated, reniform
and tiotryoidal
Cubic Submetallic Brown
C — Tetrahedral, common Resinous Yellowish
M — Cleavable, fine and Opaque to brown
coarse grained aggre- translucent Reddish
gates, compact brown
CUPBTTE Cu.O
Cubic Adamantine
C — Octahedrons, dodec- Dull
ahedrons, alone or Translucent t( in combination, com- opaque
H — Compact, granular, earthy; slender crys- tal aggregates (- cotrichiU)
cyGoole
6. RED, BROWIT, OR BLUE DT COLOR Hardness 3 to 6
Cleavage — C Fracture — F Tenacity
Yellomsh
F— Conchoidal,
brown
even, earthy
Brittle
Often with black, vamish-like
surface, passing into soft, yellow ocherouB variety. Compact limoft- Ue, maasive, with fibrous struc- ture, rather pure; brovm clay ironaUme massive or concretion- ary, impure from clay, sand; bog iron ore, porous.
Dark brown F— Conchoidal,
E 1 Olive green even
Grayish Brittle
Structure and fracture important. Fresh material is hard and heavy. With ores of lead, silver, bis- muth; also orthite, thorite, fer- gusonite.
Cherry red Reddish brown
C — None, parting
F — Uneven, splintery BritUe
4,9 J
Light brown Pale yellow
C— Dodecahedral, perfect, conapicu-
Brittle
Brownish red Dirty brown
C— Indistinct F— Uneven Brittle
ATgillaceous hemaliU, impure from clay, sand, jasper; compact hema- tite, usually quite pure.
Color and streak vary with im- purities. Extensively in lime- stone. With galena, chalcopyrite, pyrite, barite, fluorite, siderite, rhodochrosite.
Characterized by associates, usu- ally with copper minerals — mala- chite (green), azurite (blue), chalcocite and tenorite (black), chalcopyrite ( yellow ), native copper.
D.gizjcCyGoOgle
A. HOfERALS WITH METALLIC LUSTER
Streak — White, gray, green, red, brown, or yellow
CryBtalliEatioi Structure Crystals -C Maasive'M
Luster Transparency
Hexagonal Subadaman- Dark red C — Hemimorphic, rare tine Blood red
H — Compact, granular, Vitreous
' foliated Translucent to
A opaque
Goethite FeO.OH
Huebnerite MnWO,
140, 539.
Wolframite
*Ortliite (Allanite)
Orthorbombtc Submetallic Reddish brown
C — Small, thin, tabular, Translucent to Dark brown
needle-like; pa ra 1- opaque Red
lelly grouped or in
scaly fibrous velvety
crusts H — Reniform, Btalactitic
Honoclinic Submetallic Reddish brown
C — Long, fibrous, bladed, Resinous Brown
stalky, often diver- Opaque to
gent, without good translucent
terminations M— Compact, lamellar,
granular
Monocliuic Submetallic Reddish brown
C — Thick, tabular, short Opaque Dark brown
columnar, often large M — Bladed, curved lam- ellar, granular, com- pact
Ca,(Al,Ce,Fe),(A1.0H)(SiO,)i
Monodinic
C— Tabular, rare
H — Compact, granula
bladed, diesem
nated grains
Submetallic Dark brown
Resinous Blackish Opaque to brown
translucent Grayish brown
Anatue (Octahedrite)
Tetragonal
C Pyramidal, tabular, rarely prismatic
Reddish brown Yellowish brown Blackish brow D
:y
S. KED, BROWV, OR BLUE m COLOR
HaidnesB 3 to
Cleavage . Fracture -F Tenacity
Specific
Gravity
CharacteriaticH and . Associates
Reddish yellow Orange yellow
C— Basal, perfect, usually conspicu-
F-Uneven Brittle
4.B
Yellow Yellowish brown
C — Brachypinacoidal,
perfect F — Uneven, aplintory Brittle
4.B
Yellowish brown Greenish gray
C— Clinopinacoidal, perfect, conapicu-
Diatinguiahed by asaociatea — cal- otte, franklinite (black), willem- ite (yellow to green), rhodonite {flesh red). On exposure be- comes coated with the white carbonate.
Usually with other iron ores; in cavities in hematite or Lmonite. Crystals and cleavage distinguish it from limonite.
Structure, cleavage, specific gravity important. In quarts veins. With fluorite, pyrite, soheelite, wolframite, galena, tetrahedrite.
G.B
Dark red brown
perfect, conspicu-
F— Uneven Brittle
Grayish Brownish gray Pale brown
C— Pinacoidal, indis- tinct
F— Uneven ,conohoid- al
Brittle
B.6
Gray White
C— Pyramidal, basal,
perfect F-Sub-conchoidal Brittle
Distinguiahed from huebnerite by streak. Powder may be slightly magnetic. With cassiterite, quartz, mica, fluorite, apatite, scheelite, molybdenite, buebner-
Often coated with yellowish or brownish alteration product. Disaeminated in the more acid igneoua rocks; Umestone. With magnetite, epidote, quartz, f eld- Crystals often resemble elongated octaliedrons. With br o ok i t e, Tutile, ilmenite, adularta, titanite, gold.
:y
A. HDfBKALS WITH METALLIC LUSTER
Streak— White, gray, green, red, brows, or yellow
Name, Composition, and
Structure
Luster
Crystala-C
Transparency
Massive -M
BrooWte Orthorhombic
Metallic
Blackish
C— Pyramidal, (often
brown
TiO, with hexagonal
Opaque to
Blackish
Mceei habit), prismatic,
red
7fl, 347, 252
Perovsldte CaTiO,
Pseudocubic
C— Apparently cubes, highly modified, often striated
H — Reniform aggregates, rounded grains
Metallic Reddish brown
Adamantine Blackish
Opaque to brown transparent
Streak — White, gray, green, red, brown, or yellow
Gadolinite
Fe[Be(y.O)8iOJ,
Monoclinic
C — Prismatic, rough.
Submetallic Translucent t
opaque
Rdtile
TiOj or TiTiO.
Tetragonal Metallic
C — Prismatic, vertically Adamantine
striated; twinned. Opaque to
yielding knee-shaped transparent or rosette forms H — Compact, dissemi-
CASSITERITE, varieties
Tetragonal
Adamantine
Reddish brown
Ordinary
C— Thick prismatic.
Resinous
Yellowish
SnO, or SnSnO, Wood tin.
knee-shaped twins.
Dull
brown
Stream tin
common
Translucent to
Dark brown
M— Compact; reniform,
opaque
botryoidal, rounded
pebbles, often with internal, radial fib- rous structure, wood
:y
S. Red, Browit, Or Blue Dt Color
6.6 Pale yellowish C — Indistinct
8. brown F — Uneven
Gray Brittle
Crystals may be striated; not twinned like rutile. With rutile, anatase, titanite, adularia, neph-
White
Grayisli
C— Cubical, fairly 4,
distinct 4 . 1 F — Uneven Brittle
With chlorite, magnetite, serpen-
Hardness over 6
C— None 4 , F— Conchoidal, splin- 4.5
tery Brittle
C— Prismatic, pyram- 4.2 idal, not con- 4.3 spicuous
F— Uneven
Brittle
Greenish gray
In granitic rocka and pegmatites. With tergueonite, orthite, fluor- ite, molybdenite.
Pale yeUowish
brown Gray
Not as heavy aa oassiterite. Often in fine, hair-like inclusions.
quartz, felspar, iimenite, chlo- rite, brookite, apatite.
Pale yellow CIndistinct
Pale brown F — Uneven
White Brittle
Distinguished by high specific gravity. In veins cuttinggranite, gneiss; in alluvial deposits, as streom (in. With quarti, wolfram- ite, scheelite, arsenopyrite, molybdenite, tourmaline, fluorite, apatite.
:y
(Mi A.
imiERALS WITH METALLIC LUSTER
Streak— Black
Name, Composition, and
Structure
Luster
Color
References
Cryatala-C Massive -M
Transparency
W*D
.Amorphous 7
Dull
Brown
M— Earthy, sometimeB
Blackish
MnO, H,0, etc.
Moses and
with globular struc- ture
Opaque
brown
Kraus, Dana.
130. 3fi2.
CoTClIite
Hexagonal
Submetallic
Indigo blue
C— Tabular, rare
Resinoua
Blackish blue
CuS
H — Compact, granular,
Opaque
51. 294,
crusts
BORHITE (Purple copper
ore)
Cubic
Metallic
Bronze brown
C— Rare
Opaque
Copper red .
Cu,FeS,
M— Compact granular
tarnishes
readily
Draninite (Pitchblende)
Cubic
Brown
C— Octahedral, rare
Dull
Blackish
U0„ U0„ PbO, etc.
M— Botryoidal, colum- nar, curved lamellar, granular compact, apparently amor-
Opaque
brown
142, 621.
phous
Pyrrhotite
Hexagonal
MeUllic
Bronze brown
C— Tabular, rare
Opaque
Bronze yellow
FeS
M— Compact, granular
Se. 206,
Wolframite
Monoclinic
Grayish brown
C— Thick tabular, short
Opaque
Dark brown
(Fe,Mn)WO.
columnar, often large M— Bladed, curved lam-
141. 539.
ellar, granular
Hiccolite
Hexagonal
Metallic
Light copper
C— Rare
Opaque
red
NiAs
M— Compact, dissemi- nated
ijGoogle
6. RED, BROWIT, OR BLUE IH COLOR HardocM 1 to 6
Cieavage — C Fracture — F Tenacity
Dark gray Black
C— Basal, perfect
F — Uneven
Flexible in thin plates
Grayish black
C — Indistinct F— Uneven Brittle
Brownish black Grayish black
F— Conchoidal, un- Brittle
Very soft varieties soil fingers. App fly very light and floats w t due to porosity. Usu- Uy dh es to tongue. With p 1 m 1 n , siderite, pyrolusite, Im t
f 1 y haracteristic;bornite,
blue only on surface. With chalcopyrite, bornite, chalcocite.
Usually with peacock tarnish colors — purple copper ore. With chalcopyrite, chalcocite, mala- chite, casaiterite, siderite.
Structure and fracture important. Fresh material is hard and heavy. With ores of lead, silver, bismuth; also thorite, orthite, fergusonite.
Dark grayish
C— Basal,
black
spicuous F— Uneven Brittle
6.6 Black C-CUnopincoidal,
Brownish black perfect, conspicu-
6.6 Dark brownish C — Indistinct black F — Uneven
Brittle
Powder frequently attracted by magnet. Subject to dark brown tarnish. In basic igneous rocks. With chalcopsrite, pyrite, pent- la ndite, galena.
Structure, cleavage, specific gravity important. Powder may be slightly magnetic. With cas- siterite quartz mica, fluorite, apatite scheelite molybdenite,
Often with green crust of anna- berte {nickel bloom). With cobalt nickel silver minerals — smaltite proustite pyrargyrite, chloanthite native bismuth and arsenic calcite
:y
MinERALS WITH ROR-METALLIC LUSTER
StieRk — Gieen, red, brown, yellow,
or bluk
Crystalliifltion
Structure
Luster
Color
References
Cryataifl-C Massive -M
Transparency
Ozocerite (Mineral wax, naUve
Never in crystals
Waxy
Black
paraffin)
M— Compact, fibrOuB,
Submetalhc
Brownish
C„H„+.
lamellar
Translucent
black
md*
Kraiu, Dana, Panoot
280, M3, 3ft5
Hexagonal
Dull
Dark gray
lead)
C— Tabular, rare
Opaque
Iron Mack
MScaly, foliated, gran- ular, earthy, sooty
11. 273. 368
MoDoclinic
Mblaconite
Dull
Iron black
M — Earthy, sooty
Opaque
Dark gray
CuO
Sb, 332. 28B
Pitchy
Asphalt (Mineral pitch)
Amorphous
Black
Solid, or thick liquid
Brownish
C, H, 0, etc.
DuU Opaque
black
2S9. 545. 3tM
Wad
Amorphous 7
Dull
M— Earthy, sometimes
Submetallic
black
MnO,. H,0, etc.
with globular struc- ture
Opaque
Black
130. 352, 231
Lignite (Brown coal)
Amorphous
Dull
Black
M— Compact, fibrous.
Opaque
C, H, 0, etc.
commonly with
black
292. 648. 368
woody structure
Pitchy
Bituminous Coal (Soft coal)
Black
H — Compact, may show
Vitreous
C, H, 0, etc.
stratification; lamel-
DuU
black
lar, fibrous
Opaque
2B2. 5*8. 3fl6
Amorphous
Anthracite Coal (Hard coal)
Vitreous
Iron black
M— Compact
SubmetaUie
Black
C, principally
Opaque
292, 648. 3a
ijGoogle
1. DABK GRAY OR BLACK m COLOR
Hardness 1 to 3
Hard- ness
Streak
Cleavage -C Fracture -F Tenacity
Specific Gravity
Characteriatica and
YeUowiah
C — None, apparently amorphous
Plastic between fin- gers ; may be sticky
Easily indented by finger nail.
fee!. In sandstonea and ahales; with petroleum and coal.
Dark gray Iron black
C— Basal, perfect
{scales) Scales flexible
Greasy feel. Marks paper. Often impure. In crystalline limestone with garnet, spinel, pyroxenes, amphibolea; also in shale, gneiss, mica schist.
2.S
Black
F— Earthy
Coating on copper minerals, espe- cially native copper, chaloopy- rite, bornite, chrysocolla. Soils
fingers.
J.
C— None
F— Conchoidal, con- spicuous Brittle to flexible
1,8
Characteristic bituminous odor when plastic, and then sticky. Independent deposits and im-
sandstones, limestones.
Dark brown Brownish black Black
F— Earthy Brittle
Very soft varieties soil fingers. Apparently very Ught and floats on water, due to porosity. Usu- ally adheres to tongue. With psilomelane, siderite, pyrolusite, limonite.
2. Brown F — Conchoidal
2.G Blackish brown Brittle to tough
less carbonized plant May disintegrate on
exposure. Jet, compact, coal black variety with resinous luster.
2. Black F — Cubical, conchoid-
2.6 Brownish black al
Brittle
F — Conchoidal, con- spicuous Very brittle
Distinguished from other coals by conspicuous cubical fracture. Sometimes shows iridescence, or distinct plant remains. With slate, pyrite, marcasite.
Conchoidal fracture, luster, and absence of plant structure im- portant. Often iridescent. With slate, pyrite, marcasite.
jyGoogle
B. WnERALS WITH NOIT-HETALUC LUSTER
or black
Crystallization
Name, Composition, and
Structure
Luster
RefereDces
Crystals -C Massive -M
Transparency
*AUcamite
Orthorhombic
Vitreous
Greenish black
C— Slender prismatic,
Adamantine
Cu(OH)CI.Cu(OH),
usually in confused
Transparent
aggregates
to nearly
H — Fibrous, granular.
opaque
Kmu8. Dana, Panioiu
compact, crusts,
108. 322. 28B
sand
Draninite (Pitchblende)
Cubic
Pitch-Uke
Pitch black
C— Octahedral, rare
Submetallic
Brownish
U0„ UOa, PbO, etc.
H — Bottyoidal, colum-
Dull
black
nar, curved lamel-
Opaque
Greenish
lar, granular, com-
black
pact, apparently
142. 521. 27a
amorphous
Siderite
Hexagonal
Vitreous
Brownish
C— Rhombohedral,
Dull
black
FeCO,
curved or saddle-
Black
shaped, common
to opaque
M— Cleavable, granular.
compact, botryoidal
lis. 359, 223
SPHALERITE (Black Jack)
Cubic
Black
C— Tetrahedral, common
Resinous
Yellowish
ZnS
M— aeavable, fine and
Opaque to
black
coarse grained, com-
translucent
Brownish black
33. 291, 242
Cuprite
Cubic
Adamantine
Reddish black
C — Octahedrons, dodeca- Dull
hedrons, alone or Translucent t in combination, opaque
compact,
MGrauular,
earthy
Thorite (Orangite)
Tetragonal Vitreous Black
C— Square prisms with Translucent to Brownish
bipyramids opaque black H— Compact, dissemi-
:y
1. DASK GRAY OR BLACK Ht COLOR Hardness 3 to 6
Cleavage Fracture Tenacity
Characteriatica and
C — Brachypinacoidal 3.7 With other copper minerals;
F — Conehoidal 3.8 limonite, hematite.
Brittle
Olive green Dark brown eve
Brownish black Brittle Grayish black
F -Conchoids 1,
Fitch-hke appearance and fracture characteristic. Freeh material is hard and heavy. With lead, silver, bismuth minerals; also thorite, orthite, fergusonite.
— Rhombohedral , perfect, conspicu-
Curved crystals, cleavage, and rather high specific gravity char- acteristic. In ore deposits; beds and concretions in limestone and shale. With pyrite, chal copy- rite, galena, tetrahedrite, cryo- lite.
Dark brown 4. Yellowish brown Gray
3.6 Brownish red 4. Dirty brown
C — Dodeca h edral perfect, usually conspicuous
F— Conehoidal
Brittle
C — Indistinct F — Uneven Brittle
Color and streak vary with im- purities. When massive dis- tinguished from siderite by cleavage. Extensively in lime- stone. With galena, chalcopy- rite, pyrite, barite, fluorite, sid- erite, rhodochrosite.
Characterized by associates. With other copper minerals — malachite (green), azurite (blue), chalcoeit and melaconite (black, chalcopyrite (yellow), native copper.
4,6 Light orange C— Prismatic, not
6. Dark brown conspicuous
F— Conehoidal
Brittle
Dark brown to black thorite some- times contains a nucleus of yellow orangite; thorite believed to be decomposed orangite.
:y
Hiherals With Noh-Hetallic Ldster
Streak-
Sreen, red, 1>rown, yellow, or bl&ck
Name, Compoaition, and References
Crystallization Structure Crystals Massive -M
Luster Transparency
Color
Goelbite FeO.OH
Orthorhombic
C— SmaU, thin tabular, needle-like; paral-
Adamantine Dull
Translucent
Brownish
black Black
Paisons crusts
83, 348,
M— Reniform, stalactitic
Huebnerite
Monoclinic
Resm
Brownish
C— Long fibrous, bladed.
S bm tall
black
stalky; often divergent, without good terminations H — Compact, lamellar,
T lu nt t paque
Black
140, 538,
granular
Wolframite
Submetallic
Dark gray
t— Thick tabular, short
Opaque
Brownish
(Fe,Mn)WO.
columnar, often large M— Bladed, curved lam-
black Iron bUck
141. 539.
ellar, granular
HORHBLEHDE (Amphibote)
Vitreous
Pitch black
C — Long prismatic.
SUky
Greenish
Silicate of Ca, Mg, Fe, Ai
etj'..
prism angle 124°;
black
often with rhombo-
opaque
Brownish
hedral-like termina-
black
tions
M— Bladed, fibrous.
253. 387.
granular, compact
AUGITE (Pyroxene)
Monoclinic
Vitreous
Pitch bUck
C— Short prismatic;
SubmetalUc
Greenish black
Silicate of Ca, Mg, Fe, A!
etc.
Translucent to
Brownish
prism angle 87°
black
M— Compact, granular.
245. 390.
3S5
Amorphous T
Submetallic
Iron black
M— Botryoidal, reni-
Dull
Bluish black
MnO„ BaO, H,0, etc.
form, stalactitic;
Opaque
Dark gray
128, 352,
smooth surfaces
ijGoogle
1. Dark Gray Or Black Hi Color
Hftrdnen 3 to B
4,6 Yellow C — Brachypinacoidal
6.6 Yellowish FUneven, tpiintery
brown Brittle
C — CliDopinacoidal, perfect, conspicu-
Structure, cleavage, and high specific gravity characteristic. lo quarts veins. With wolfram- ite, fluorite, pyrite, echeelite, galena, tetrahedrite.
Dark reddish
C — Clinopinacoidal,
brown
Black
F— Uneven Brittle
Grayish green
CPriamatic, perfect,
Grayish brown
often coDspicuoua
YeUow
—124= Brittle
Distinguished from huebnerite by streak. Powder may be slightly magnetic. With cassiterite, quarti, mica, fluorite, apatite, scheelite, molybdenite, hueb-
Simple, pseudohexagonal crystals, and cleavage at 124° important. Very common; in nearly all types of rocks. With calcite, quarts, feldspar, pyroxene, chlorite.
Pale green Grayish green
C — Prismatic, perfect,
conspicuous — 87° Brittle
Black F — Conchoidal,
Brownish black even
Brittle
Crystals usually eight-sided, more rarely four-aided; pseudotetrag- onal with prism angles of 87° and 93". Cleavage less distinct than on hornblende. Common in basic eruptive rocks and crystal- line limestones.
Often with fine sooty coating of pyrolusite. With other manga- nese minerals; also limonite.
jyGoOgIc
B. IHHERALS WITH HOH-HETAIXIC LUSTER Streak— Green, red, brown, yellow, or black
Crystallizatior Structure CryatalaC HaBBive — M
Transparency
Chromite
Cubic
Submetallic
Iron black
C— Octahedral, rare
Pitchy
Brownish
(Fe,Cr)[(Cr,Fe)OJ,
KiBiu, Duu,
pS
M— Compact, granular, disseminated grains
Opaque
black
158. Ml.
MoQOclinic
SubmetaiUc
Orthite (AUanite)
Black
C— Tabular, rare
Greasy
Pitch black
Ca,( AI.Ce.Fe) ,( Al , OH) (SiO.) ,
H — Compact, granular, bladed, diasemi-iBtrod
Translucent to opaque
Brownish
black
grama
201. 440,
40S
Brookite
Adamantine
Iron black
TiO,
Only in crystals,— py- ramidal (often with hexagonal habit),
Metallic
Opaque
Reddish black Brownish black
IlTaite
Orthorhombic
Vitreous
Black
C— Columnar, acicular,
Submetallc
Greenish black
CaFe,CFe-OH)(SiO.),
vertically striated
M— Compact with .radial
fibrous structure;
Opaque
Brownish black
196.
granular
Stieak— Green, red, brown, yeUow,
or black
CHUjaiTOin
Monoolinic
Vitreous
Dark gray
H,FeAliO,
C— Tabular, six-sided M~Foliated, scaly, platy
Pearly
Greenish gray Greenish black
Tetragonal Adamantine Iron black
C — Prismatic, vertically Metallic Brownish
striated; twinned, Opaque to black
yielding knee-shaped transparent Reddish black or rosette forms M— Compact, dissemi-
:y
1. DARK GRAY OR BLACK m COLOR
Cleavage -C
Fracture Tenacity
Dark brown C — Indistinct
Grayish brown F — Uneven, conchoid-
May be slightly magnetic. Pitch' like appearance characterietic. With serpentine, chrome garnet, laratite; also in black sands, platinum placers.
Pale brown C — Pinacoidal, indis-
Grayish brown tinct
F — Uneven, conchoid-
C — Indistinct
F — Uneven Brittle
Often covered with yellowish or brownish alteration product Disseminated through the more acid igneous rocks; also in lime- stones. With magnetite, epidote, quartz, feldspar.
Crystals may be deeply striated; not twinned like rutile. With rutile, anatase, titanite, aduiaria, nephelite.
G.5 Blackish
C — Pinacoidal F — Uneven Brittle
Often covered with yellowish alteration product and, hence, softer. With dolomit, pyroxene, iron minerals.
HrdneSB orer 6
Pale green
C— Basal, perfect,
conspicuous F-Scaly Brittle
Pale yellow Pale brown
C— Prismatic, pyrar idai, not con spicuous
F— Uneven
Brittle
Sometimes softer due to alteration. Easily recognized by micaceous structure and perfect cleavage. In clay slates, mica schists. With corundum, garnet, chlorite, hornblende.
4,2 Not as heavy a
Often
Widely distributed. With quartz, feldspar, hematite, ilmen- ite, chlorite, brookite.
:y
B. MINERALS WITH NON-HETALLIC LDSTER Streak — Green, red, brown, yellow, or black
CryHtalKBatioi Structure Cryetflla -C Maeeive - M
Transparency
CASSITERITE Tetargonal
C — Thick prismatic; SnO, or SnSnO, knee-shaped twins
H — Compact, reniform, botryoidal, rounded UoHB pebbles, often with-
Kraiw, Dana. Pmoiu internal, radial
80. 344, 249 fibrous Structure
CORnHDlIM, variety Hexagonal Dull
Emera U — Fine to coarse gran- Submetallic
A1,0„ with Fe,0„ Fe,0„ 8iO, ular Opaque
Submetallic
BUck
DuU
Brownish
Translucent to
black
opaque
SPIHEL, varieties
Cubic
Vitreous
Black
Hercynite
C— Octahedral, smaU
Dull
Brownish
R"(R"'0,). PieotiU
H — Compact, granular.
Nearly opaque
black
R" =Mg, Fe,
disseminated grains
Zn, Mn
R"'=A1, Fe
Is7. 338,
streak
— Dncolored, white, or light gray
GYPSUM, varieties
Pearly
Dark gray
SeUnite
C— Tabular, prismatic;
VitreouB
Black
CaS0,.2H,0 Safin spar
M— Cleavable, coarse
fibrous, foliated, earthy, sand
Silky Dull
Transparent to opaque
140. S3I.
*HALITE (Rock salt)
Cubic Vitreous Dark gray
C — Cubes, often skeletal Translucent to Black
or hopper-shaped nearly opaque
H — Compact, granular,
cleavable, fibrous,
crusts
:y
1. Dask Gray Or Black If Color
HacdneM over 6
Cleavage — C Fracture -F Tenacity
Pale browD
C— Indietinct
Pale yellow
F— Uneven
Brittle
Distinguished by high specific gravity. In veins cutting gran- ite, gneiss; in alluvial deposits as stream tin. With quartz, wol- framite, scheelite, arsenopyrite, molybdenite, tourmaline, fluor- ite, apatite.
YeUowifih
C— Indistinct
brown
F — Uneven
Black
Brittle to tough
lagnetite.
Grayish green Pale brown
tinct F— Conchoidal BritUe
Hudnesa
WHte
perfect, conspicu- ous; pyramidal, orthopinacoidal
F-Conohoidal
Brittle, lamellie flex- ible
2.fi
White
C— Cubic, perfect
F— Conchoidal Brittle
3.7 Corundum mixed v
4.3 hematite, quart
iron ore. Powder may be mag- netic. Properties vary with composition. With mica, amphi- bole, chlorite, spinel; in crystal- line limestones, schists, peri- dotites.
3.9 Commonly in basic igneous rocks,
4.1 especially the olivine-bearing types. With olivine, serpentine, corundum, magnetite, horn- blende, garnet.
Color due to organic material. Selenite, crjtals and cleavage plates; satin spar, fibrous, with silky luster. In limestones, shales. With halite, celestite, sulphur, aragonite, anhydrite, ore deposits.
Color due to organic matter. Characteristic cubical cleavage and saUne taste. May absorb moisture and become damp. With shale, gypsum, anhydrite, polyhalite.
:y
B. HUfERALS WITH NON-UETALLIC LUSTER
Streak— TTncolored, white, or light gray
Name, Composition, and References
Cryetallizatiou Structure Crystals "C Massive M
Traitsparency
APATITE, variety HexagoDal Dull
Phosphate rock H — Compact, fibrous, Opaque
CaJ'{PO,)„ in part nodular, reniform,
Moses earthy
497,
CRYOLITE Monoclinic Vitreous Brownish
C — Small, paeudocubical, Greasy black
AlF,,3NaP rare Translucent to Blackish
M — Cleavable, granular nearly
opaque
321,
31S
BIOTITE (Black mica) Monoclinic Pearly Black
C — Tabular, with hex- Submetallic Brownish
(K,H),(Mg,Fe)j(Al,Fe)j-(SiO.), agonal or rhombohe- Transparent to black
dral habit opaque Greenish black H — Plates, disseminated
215,
4B7,
Limestone Marble StagmiUe Travertine
Hexagonal Vitreous Dark gray
M — Cleavable, granular. Dull Brownish
fibrous, banded, Translucent to black
stalactitic, oolitic, opaque Black
porous, compact,
crusts, shells
111,
354,
Streak— Uncolored, white, or light gray
Orthorhombic Vitreous Dark gray
C— Thick tabular, pris- Pearly Blackish
matic, rare Translucent to
M — Granular, compact, opaque
fibrous, lamellar,
cleavable
.jGooglc
1. DARK GRAY OR BLACK m COLOR
Haidnesa 1 to 3
Cleavage -C
Fracture — F Tenacity
Specific Gravity
Characteristics and
F— Conchoidal, Brittle
More or leas impure "nasaes, fre- quently resembling compact bi- tuminous limestone. Independent beds, nodules, or concretions.
White
C-Basal, prismatic, perfect, nearly
conspicuous F— Uneven Brittle
White Grayish
C— Basal, perfect,
Tough, lamelte of fresh biotite very elastic
White
Gray
C— Rhombohedral,
perfect F— Conchoidal Brittle
Often contains disseminated sid- erite, chlacopyrite, galena, pyrite, sphalerite, fluorite, columbite.
Easily recognized by structure, highly perfect cleavage, and elasticity. Important constitu- ent of many igneous and meta- morphic rocks — granite, syenite.
Rombohedral cleavage generally observed. Cleavages often striated. Yields bituminous odor when struck with hammer. Tp distinguish varieties, see refer-
CPinacoidal, per- fect, .3 directions at ilO"
F— Conchoidnl
Brittle
Color due to organic matter. Pseudocubical cleavage some- times noted. Granular varieties resemble marble. In limestones, shales. With halite, gypsum.
:y
B. HIHERALS WITH ROn-HETALUC LUSTER
Streak — Uncolored, white, or light gnj
Crystallization Structure Crystals -C Massive— M
CERDSSITE PbCO,
Knwu.,
Duim
aaa.
and
Psraoni
aaa
Orthorhombic
C— Tabular, prismatic, pyra midal; peeudo- hexagonal, clusters or star-shaped group
M— InterUced bundles, granular, stalactitic, compact, eartliy
Greasy
Silky
Translucent to opaque
Grayish black Black
SERPEirraiE H,Mgi,0,
Orthrohombic T C— Unknown
M— Compact, columnar, fibrous, lameUar, granular
Hexagonal
M— Compact, fibrous,
nodular, reniform,
earthy
Greasy Waxy Translucent to
opaque
Greenish black
Brownish black
APATITE, variety
PhospkaU Ca(PO,)impart
Dull Opaque
Black
♦WsveUite
(Ai.0H).(P0.),.5H,0
Orthorhombic C— Capillary, small M— Crusts, globular or
radial fibrous struc-
Vitreous
Black Dark gray
180,
512,
ture
Dolomite
CaMg(CO,
Hexagonal
H — Coarsely crystalline,
compact, granular,
friable
Vitreous Translucent to opaque
Grayish black
Brownish black
115,
M— Cleavable, fine or coarse grained, com- pact
Hexagonal
C— Rhombohedral, rare
MGranular, compact, earthy
SPHALERITE (Bia ZnS .
Submetallic Opaque to translucent
Vitreous Dull
Translucent to opaque
Black Brownish
Yellowish
black
♦MAGHESITE MgCO,
Grayish black
black
lis.
35S.
ijGooglc
1. dase: gray or black dt color
Cleavage -C Fracture — F
Tenacity
Gravity
Characteristics and
Aaaociates
3. White 3.6 Gray
C— IndistiDct F — CoQchoidal Very brittle
Color due to admixture of fine particles of galena. Twinning, atnicture, luster, and bigh spe- cific gravity characteristic. With lead minerals — galena, pyromorphite, anglesite; also malachite, limonite.
F— Conchoidal, splin- tery BritUe
F — Conchoidal,
Brittle
C— Pinacoidal, do-
F — Uneven, fibrous Brittle
Smooth and greasy feel. Ottn spotted, clouded, multi-colored. Sometimes crossed by seams of asbestos (chrysotile). With mag- nesite, calcite, chromite, gar- nierite, pyrope, platinum.
More or less impure masses fre- quently resembling compact, bi- tuminous limestone. Independ- ent beds, nodules, or concretions.
Secondary mineral, occurring on surfaces of rocks or minerals as crystalline crusts with pronounc- ed radial fibrous s
3.6 White 4, Gray
C — Rhombohedral F — Conchoidal Brittle
C— Dodecahedral, perfect, usually conspicuous
F — Conchoidal
Brittle
C — Rhombohedral, per- fect (crystals) F — Conchoidal, conspic-
Tough to brittle
Color largely due to organic mat- ter; yields bituminous odor when struck with hammer; may be banded. In independent beds, fissures, and cavities; ore deposits.
Color and streak vary with im- purities. Extensively in Ume- stoneS with galena, chalcopyrite, pyrite, barite, fluorite, siderite, rhodochrosite.
Conchoidal fracture generally prominent. Compact varieties apparently very hard. Dissemi- nated in talcose and chloritic schists, serpentine, gypsum; independent deposits.
:y
B. Huterals With Hoh-Metallic Luster
StreRk— Uncolored, white, or light gray
Crystallisation
Structure Crystals -C Massive— M
FLUORITE (Pluor spar)
Cubic Vitreoua Purplish
C — Cubes, alone or modi' Transparent to black
fled, well developed, nearly Brownish
common; penetra- opaque black
I tion twins Black
a M — Cleavable, granular,
Huebnerite MnWO.
Monoclinic Resinous Brownish
C— Long fibrous, bladed, Submetallic black
stalky, often diver- Translucent to Black
gent, without good opaque
— Compact, granular
lamellar.
TITAIHTE (Sphene) CaTiSiO.
Monoclinic
C — Wedge- or envelope- ahaped when dissem- inated; tabular or prismatic when at- tached
H — Compact, lamellar
Vitreous Submetallic Translucent to opaque
Black Brownish
HORHBLEHDE (Amphibole) Silicate of Ca, Mg, Fe, Al, etc.
Silicate of Ca, Mg, Fe, Al,
1 Hyperalhene
(Fe,Mg),(SiO.),
Monoclinic
Vitreous
Pitch black
C— Long prismatic, prism
SUky
Greenish
angle 124°, often
black
with rhombohedral-
opaque
Brownish
like terminations
black
M— Bladed, fibrous, gran-
ular, compact
Monoclinic
Vitreous
Pitch
C— Short prismatic.
Submetallic
black
thick columnar.
Translucent to
Greenish
prism angle 87°
opaque
black
M— Compact, granular,
Brownish
disseminated
black
Orthorhombic
Pearly
Black
C— Prismatic, tabular.
Metalloidal
Browmsh
rare
Translucent to
black
M- — Granular, foliated.
Greenish black
cleavable aggregates
ijGooglc
1. Dark Gray Or Black Ih Color
HardBMS 3 to 6
Hard-
Streak
Cleavage =-C Fracture -F Tenacity
Specific
Gravity
Characteristics and Associates
White
tect, conspicuous Brittle
Easily recognized by crystal form and octahedral cleavage. Com- mon gangue mineral of metallic ores, especially galena, sphalerite, cassiterite; also with calcite, quarts, barite.
Greenish gray
C — Clinopinacoidal, perfect, oonepic-
BritUe
Structure, cleavage, and specific gravity characteristic. In quartz veins. With wolframite, fluorite, pyrite, scheelite, galena, tetrahe- drite.
White Gray
C— Prismatic, conspic- uous partings often noted
F— Conohoidal
Brittle
With feldspars, pyroxenes, amphi- boles, chlorite, scapohte, sinion.
Gray
Greenish gray Browineh gray
C — Prismatic, perfect often conspicuous
—124='
Simple, pseudohexagonal crystals, and cleavage (124°) important.
types of rocks. With feldspars, quarts, pyroxenes, chlorite.
White Gray
—Prismatic, perfect, conspicuous — 87°
s.
White
C— Brachypinacoidal,
Gray
perfect, conspicuous
Brownish gray
F— Uneven Brittle
Crystals usually eight-sided, more rarely four-sided; pseudotetrag- onal with prism angles of 87° and 93°. Cleavage less distinct than on hombtende. Common in basic eruptive rocks and crys- talline limestones.
Copper red iridescence often noted, due to small tabular inclusions. Commonly in the more basic igneous rocks. With feldspar (tabradorite), ohvine, hornblende, pyrrhotite, magnetite.
:y
B. Hdierals With Hoh-Hetallic Luster
streak
— Uncotored, white, or light gray
CryataUi.ation
Structure
Luster
Crystals -C Massive -M
Transparency
Orthite (AlUnit)
MoDocUmc
SubmetaUic
Black
C— Tabular, rare
Greasy
Pitch black
Ca,(Al,Ce,Fe),(Al.OH>(Si0.).
H — Compact, granular.
Translucent to
Brownish
Uobs
opaque
black
Knua, DuiB
Panoiui Sraina
201. 440.
Aiuttaw (Octahedrite)
Tetragonal
Metallic
Black
C— Pyraiilidal, tabular.
TiO,
rarely priHinatic
Opaque to
black
78. 348,
Reddish black
Broofcite
Orthorhombic
Adamantine
IrtHi black
Only in cryBtalB,— py-
Metallic
Reddish black
TiO,
ramidal {often hex- agonal habit), priB-
Opaque to
Brownish black
16. 347,
matie, tabular
Perovskite
Pseudocubic
SubmetalUc
Black
-C — Apparently cubes.
Adamantine
Grayish
CaTiO,
often Btriated H— Reniform aggregates,
Opaque
thick
Brownish
black
238, 487.
rounded grains
Streak
— UDC0k>rBd, white, or light gray
Labradorite (FeldBpar)
Triclinic
Vitreous
Daikgray
C— Thin tabular, often
Pearly
Greenish
Silicate of Na,Ca,Al
with rhombic cross- aection M-Compact, cleavable.
Translucen
to nearly opaque
gray
268. 379.
granular
Ca,{Al,Fe),(Al,OH)(SiOJ,
Honoclinic Vitreous Greenish
C — Prismatic, elongated Translucent to black and deeply striated opaque parallel to 6 axis; generally terminated on one end only H — Columnar, fibrous, parallel and diver- gent, granular
:y
1. Dark Gray Or Black Ih Color
Cleavage — C
Fracture — F Tenacity
Characteristioa and
Aaaociates
S.5 Gray C — Pinacoidal, iodis-
6. Greenish gray tinct
Brownish gray F — Uneven, conchoidal
Brittle
Gray C — Indistinct
Yellowish white F — Uneven Brownish white Brittle
Often covered with yellowish or brownish alteration product. Disseminated through the more acid igneous rocks; limestones. With magnetite, epidote, quarts.
6.fi
Gray
C— Pyramidal, basa!
3,8
Crystals often resemble elongated
B.
White
F — Subconchoida 1 Brittle
octahedrons. With brookite, rutile, ilmenite, adularia, titanite, gold.
Crystals may be deeply striated; not twinned tike rutile. With rutile, anatase, titanite, adularia, nephelhe.
White Grayish
C— Cubical, fairly dis- 4,
tinct 4,1 F-Uneven Brittle
With chlorite, magneUte, lime- stone, serpentine.
Hardness over 6
White
C— Baaal, brachypina- 2,7 eoidal, periect,
conspicuous— 56"
Often with play of colors — yellow, green, blue, red. Inclined cleav- ages are striated. In basic igne- ous rocks. With pyroxenes, amphiboles.
Brittle
6. White
7. Grayish
C — Basal, perfect F — Uneven Brittle
Crystals are often dark green or blackish green, massive aggre- gates lighter colored. Widely distributed. With quartz, feld- spar, garnet, hornblende, pyrox- ene, prebnite, magnetite, native copper.
:y
B. lOHERALS WITH nOK-HETALUC LUSTER
Streak — Dncolored, white, or light gray
Crystallization Structure Cryetalfl -C
Massive -M
Monoclinic
C— Tabular, six-sided iO, M— Foliated, scaly,
Moaea plBty, granular;
Kraus. Dana, Parsons f"" *ld sheaf-like
228. 471, . . . aggregates
Luster Transparency
Vitreous Dark gray
Pearly Greenish gray
Translucent to Greenish black opaque
Gadolinlle
FeIBe(Y.O)8iOj,
Monoclinic
C — Prismatic, rough, r H — Compact, d i s s e i
Vitreous Black
Greasy Greenish
Translucent to black opaque
Tetragonal Metallic Iron black
C — Prisma tic, vertically Adamantine Brownish
striated; twinned, Opaque to black
yielding knee-shaped translucent Reddish black or rosette forms H — Compact, dissemi-
Cassiterite
Tetragonal
Submetallic
Black
C— Thick prismatic, knee-
Dull
Brownish
SnOj or SnSnO,
shaped twins, quite
M— Compact, reniform. botryoidal, rounded pebbles, often with internal, radial
Translucent to opaque
black
80,
3i4, 249
fibrous structure
OAKHET, varieties
Cubic
Vitreous
Velvety black
AndradUe,
C— Dodecahedrons, te-
Brownish
R,"R,"'(8iOJ,
AlmandiU
tragonal trisoctahe-
opaque
black
R"=Ca.Fe,Mg
drons, alone or in
R"'=Al,Fe
combination M — Granular, compact, lamellar, diBsemi-
208,
nated, sand
ijGoogle
1. DAS£ GRAY OR BLACK IH COLOR Hanloess over 6
Cleavage ="C Fracture -F Tenacity
White C— Basai, perfect,
Greenish white spicuous
Gra5ish F— Scaly
Brittle
!s softer due to alteration. Easily recoguixed by micaceous structure and perfect cleavage. In clay slates, mica schists. With corundum, garnet, chlorite, hornblende.
Oreeniah gray
C— None
4,
In granitic rocks and pegmatites.
tery
With ferguBonite, orthite, fluor- ite, molybdenite.
Brittle
Gray
CPriamatic, pyrami-
Not as heavy as cassiterite. Often
YeUowish white Brownish white
dal, not conapicu-
F— Uneven Brittle
in hair-like inciuaions. Widely distributed. With quartz, feld- spar, hematite, ilmenite, chlorite, brookite.
White C — Indistinct
Yellowish white F — Uneven Brownish white Brittle
Distinguished by high specific gravity. In veins cutting gran- ite, gneiss; in alluvial deposits as tlreamtin. With quarts, wolfram- ite, Bcheelite, molybdenite, tourmaline, fluorite.
C — Dodecahedral, i:
ally indistinct F — Conchoidal, une Brittle
AndradUe, commonly with mag- netite, epidote, feldspars, nephe- lite, leucite; almandiU, with mica, ataurolite, andalusite, cyanite, tourmaline.
jyGoogle
B. HinBRALS WITH hoh-metallic luster
Streak
— Uncolored, white, or light gray
References
Crystallization
Structure Crystals Massive -M
Luster
Transparency
Color
Qdartz,
sio.
variety
Smoky quartz
Hexagonal
C— Prismatic, horizon- tally striated M — Compact, granular
Vitreous Transparent to translucent
Grayish black Brownish black
Cryptocrystalline
varieties
Chalcedony
Onyx
Flinl
BasanUe
Moees KrauB, Dana. 70. 324. 372
Hexagonal
Fine cryetalline masses, banded, nodular,
botryoidat, stalactitic
Waxy
Vitreous Translucent to
opaque
GrayiBh black Brownish black
Velvet black
TOURHALDfE
M,'Al,(B.OH)sSi,0., M'=Na, K, Li, Mg, Fe
Hexagonal
C— Prismatic, vertically striated; terminated with broken or rhom-
Pitchy Vitreous
opaque
Pitch black Brownish
black Bluish black
bohedral-hke sur- faces; well developed crystals are hemi- morphic H — Compact, divergent columnar
Staurolite
Fe(A10),(A1.0H}(8iO,),
Orthorhombic Vitreous Brownish
C— Prismatic; twins plus- Dull black
( +) or X-shaped, Translucent to Dark gray
well developed, often opaque
SPINEL, varieties
Cubic
Vitreous
Brownish
PleonasU
C— Octahedral, well de-
Dull
black
R"(R"'0,), Gakniie
veloped, common
Nearly opaque
Grayish black
R"-Mg, Fe, Dysluite
H — Compact, granular,
Greenish black
Zn, Mn
R"' AI, Fe
157, 338, 341
ijGoogle
1 . DARK GRAY OR BLACK I H COLOR Hardness over 6
Cleavage — C Fracture -F Tenacity
Specific Gravity
Characteristic coachoidal fracture and glassy luster. Common in granitic rocks.
C — Indistinct
F — Conchoidal, e
spicuouB Brittle to tough
Conchoidal fracture characteristic. Chalcedony, waxy luster; onyx, banded; JliiU, generally with white coating; baaaniU, velvet bUck.
White
C— None
Spherical triangular cross-section,
Gray
F— Conchoidal, un- Brittle.
a
coal black color, and lack of cleavage important. In peg-
luvial deposits- With quarts, feldspar, cosmterite, beryl, topas,
fluorite.
White
C— Brachypinacoidal
Fresh crystals usually possess
Gray
Brittle
bright and smooth faces, when altered dull, rough, softer, and
with colored streak- In meta- morphic rock s — gneiss, m i'c a schist, slate. With cyanite, garnet, tourmaline, sillimanite.
White
C— Octahedral,
indis-
Commonly aa contact mineral in
Grayish
tinct F— Conchoidal
granularlimestones; in more basic igneous rocks; rouuded grains in pUcers. With calcite, chondro- dite, serpentine, brucite, corun- dum, graphite, pyroxene.
ijGoogle
B. Minerals With Hon-Hetallic Ldster
Streak— Dncolored, white, or light gray
Crystallization Structure Crtals-C Massive — M
Transparency
DIAMOND, varieties
DiamoTid proper C BoH
Carbonado
Cubic Adamantine Black
C — OetahedrowB, hexoc- Vitreous Dark gray
tahedroDS, usually Translucent to with curved surfaces opaque M— Rounded or irregular grains or pebbles, of- ten with radial struc- Moaea ture
Ktaus, Duis, PananB
271,
3se
DigitzcdCyGoOgIC
1. DARK GRAY OR BLACK IH COU>R Hudneu over 8
Cleavage —C Fracture — F Teoacity
C — Octahedral, perfect
(diamo&d proper) F — Couchoidal Bnttle
Characterietics and
Diamojid proper, crystals and cleavage fragmenta; bort, trans- lucent with radial structure, also crystal fragments; carbonado, granular to compact, opaque. In serpentine rocks — kimberlite, peridotite — called bltie grouTui, or in placers. With pyrope, mag- netite, chromite, cassiterite, sir- con, gold.
:y
B. HOfERAIS WITH HOH-HETALLIC LUSTER
Streak— Pink, rd, brown, ot jeUow
Name, Composition, and Reterences
Structure
Cryrtala-C
Mflsaive-M
Luster
Transparency
Color
Bauxite A1,0(0H).
KmuB, M. 3B0.
Psreoni
Never in crystals M— Pisolitic, oolitic, rounded disBemi- nated graina, clay- Uke, earthy
DuU
Earthy Opaque
Red Reddish brown
HEMATITE, varieties
Redocher Fe,0, Oolite
Fi/siUiferou
HexagooHl
H — Fine granular, earthy,
oolitic, replacement
of sheila
Dull Opaque
Brownish
red Cherry red
ae. 334.
Errtbrite (Cobalt bloom) Co,{A80.),.8H,0
Monoclinic Resinous Aurora red
C — Short prismatic, rare Transparent to Orange
H — Granular, compact, translucent yellow incrustations
Monoclinic Adamantine Crimson
C— Acicular, vertically Dull Peach red
striated, small, rare Transparent Pink H — Globular, reniform, to opaque
earthy, crusts, stains
Hexagonal Adamantine Scarlet red
C — Rhombohedral, thick Dull Brownish red
tabular, small Transparent to H — FinegranuIar,fibrous, opaque
earthy coatings
Proustite
Ag,AsS,
Hexagonal Adamantine Scarlet
C — Sniall, complex, rare Dull Vermilion
M-— Compact, dissemi- Translucent to
nated, crusts, bands transparent
Crocoite PbCrO,
Monoclinic Adamantine Hyacinth red
C — Prismatic, acicular Greasy Aurora red
M — Columnar, granular, Translucent
:y
2. PIHE, RED, OR RED VIOLET m COLOR
Cleavage -C Fracture — F Tenacitjr
Cherry red C — None
Reddish brown F— Earthy Brittle
Color and streak variable, due to pigments. Clay odor when breathed upon. Distinguished from clay by pisoUtic or oolitic structure. With clay or kaolinite in nodules, grains, or irregular de- posits in timestoae or dolomite.
Red ocher, red earthy variety; ooWieftemnitte, fish-egg structure; foaaili/erota hematite, replace- ment of shells.
l.B Orange yelloi
C — Clinopinacoidal,
F — Conchoidal
Slightly sectile
2.6 Orange yellov
Frequently disseminated in clay or dolomite. With orpiment, stibnite, native arsenic, pyrite, barite, calcite.
C- — C linopinacoidal ,
F— FbrouB, earthy Sectile, thin la mime flexible
Crystals frequently in spherical or stellate groups with velvety surface. Usually earthy. Color fades on exposure. Common al- teration product of oobalt- arsenie minerals — cobalt! te, smal- tite, chloanthite.
C — Prismatic, not c
spicuous F — Uneven Brittle to sectile
C — Imperfect F — Conchoidal Brittle
C — Basal, prismatic F — Conchoidal, unevel Sectile
Characterized by color, streak, and high specific gravity (often lowered by gangue). Dissemi- nated through silicious rocks. With native mercury, pyrite, marcasite, realgar, stibnite.
LigAf ruby sUver ore. Distin- guished from cinnabar by associ- ates. With pyrargyrite, in veins with other silver minerals and galena. Compare pyrargyrite
Resembles potassium bichromate in color. Alteration product of galena. With galena, quarts, pyrite, vanadiaite, wulfenite.
:y
B. BOnERALS WITH ROIf-HETALLIC LUSTER
Streak— PJnk, red, brown, o
Crystallization id Structvire
CryatalB-C Maaaive - M
Tranaparency
Pyrarynte
Hexagonal
C— Small, complex, rare
K— Compact, diBBemi-
nated, crusts, bands
Adamantine MetalUc Transparent to opaque
Dark red
KtauB.
Dua.
PflnBQB
WuUeDite PbMoO,
13S.
Ml.
26S
Tetragonal
C— Square, thin tabular, more rarely pyrami- dal
M— Coarse, fine granular
Resinous Adamantine Transparent to
Orange red Bright red
Vanadinite Pb.CI(VO,
2S1
Hexagonal
C— Prismatic, small, at
times skeletal M — Compact, globular,
fibrous, crusts
Resinous Translucent to opaque
Ruby red Brownish red Orange red
Streak— Pink, red, brown, or yelknr
BEHATITE, varieties
Hexagonal
Submetallic
Brownish red
m
H— Compact, granular.
Dull
Dark red
Fe,0, Compact
columnar, splintery, radiated reniform or
Opaque
8e, 334.
botryoidal
Sphalertte
Cubic
Greasy
Brownish
C— Tetrahedral, common
SubmetalUc
red
ZnS
M— Cleavable, fine to coarse granular, com-
opaque
Yellowish red
33, 291,
2*2
pact
Coprtte
Cubic
Adamantine
Cochineal red
C— Octahedrona, dodeca-
Dull
Brick red
Cu,0
hedrons, alone or in
M— Granular, earthy; slender crystal ag-
gregates (chalca-
Translucent to opaque
Dark red
tTwkUe)
ijGoogIc
3. Pikk, Red, Or Red Violet Is Color
Hardneas 1 to 3
Cleavage ="0 Fracture -P Tenacity
2.6 Cherry red 3. Purplish red
C — iDdiatinct F — Conchoidal Brittle
Frequently as gray or dark red bands. Darker than proustite dark rubj/ silver ore. With proust- ite, in veins with other silver minerals and galena.
Lemon yellow C — Pyramidal, india- Pale yellow tinct
F — Conchoidal, uneven
Brittle
Square plates, sometimes with . forms of the third order. With lead miaerala — galena, pyromor- phite, vanadinite.
C— None
F — Conchoidal,
Brittle
Crystal faces smooth with sharp edgea. With lead minerals but never in large quantities.
Cherry red C — None
Reddish brown F — Uneven, splintery Brittle
ArgilloMous hematite, impure from clay, sand, jasper; compact hema- tite, usually quite pure.
— Dodeeahedral, per- fect, usually con-
Pale yellow Brownish yellow
Brownish red C — Indistinct
Dirty brown F — Uneven
Brittle
Color and streak vary with impuri- ties. Extensively in limestone. With galena, chalcopyrite, pyrite, barite, fluorite, siderite, rhodo- chroaite.
Characterized by associates, cop- per minerals — malachite (green) azurite (blue), chalcocite and melaconite (black), chalcopjrrite (yellow), native copper.
:y
B. HIirERALS WrrH HOH-BIETALLIC LUSTER Streak — Pink, red, tn'own, or yellow
Name, Composition, and
CrystalliKBtion
Structure Crystals -C Massive — M
Transparency
Zincite
Hexagonal
Adamantine
Dark red
C— Heminorphic, rare
Vitreous
Blood rM
ZnO
H — Compact, granular, MiBM foliated
Translucent to opaque
Kraiu.
Dana.
Famous
S4.
Xenotime
Tetragonal
Greasy
Flesh red
C— Pyramidal, prismatic
Vitreous
Brownish red
M— Compact, dissemi- nated, rounded
Translucent to opaque
Yellowish red
lae,
494,
grams
Goethite
Orthorhombio
Adamantine
Reddish
e-mail, thin tabular,
Dull
Brownish red
FeO.OH
needle-like; paral-
Translucent
lelly grouped or scaly, to opaque fibrous, velvety (Moists M— Reniform, stalactitic
Huebnerite MnWO.
Wolframite
(Fe,Mn)WOj
Rotile
TiO, or TiTiO.
Monoclinic Greasy
C — Long, fibrous, bladed, Submetallic
stalky; often diver- Translucent
gent, without good to opaque
M — Compact, lamellar,
granular
Monoclinic Submetallic
C — Thick tabular, short Opaque
columnar, often large H — Bladed, curved lam- ellar, granular, corn- Tetragonal Adamantine C — Prismatic, vertically Submetallic striated; twinned. Translucent yielding knee-shaped opaque
M — Compact, disaemi-
:y
3. PHTK. RED, OR RED VIOLET Iff COLOR
HardnesB over 3
Cleavage — C Fracture -F Tenacity
4. Orange yellow 4.S Beddish yellov
C — Basal, sometimes
conspicuous F— Uneven
Brittle
Associates important — calcite, franklinit (black), willemite (yellow to green), rhodonite (flesh red). On exposure be- comes coated with the white carbonate.
Pale brown C — Prismatic
Yellowish F — Uneven, splintery
Reddish Brittle
4.B Yellowish C — Brachypioacoidal
6.6 Yellowish brown F — Uneven, splintery Brittle
Commonly as loose, disseminated, or attached crystals resembling zircon, but softer. In granite and gneiss with zircon; alluvial deposits.
Usually with other iron minerals; in cavities in hematite or limonite.
Yellowish brown C — Clinopinacoidal, per- fect, conspicuous Brittle
Structure, cleavage, and specific gravity characteristic. In quarts veins. With wolframite, fluorite, Bcheelite, galena, tetrahedrite.
C — Clinopinacoidal, perfect, conspic-
Distinguished from huebnerite by streak. Powder may be slightly magnetic. With cassiterite, quartf, mica, scheelite, molyb- denite, huebnerite.
C — Prismatic, pyrami-
FUneven Brittle
Not as heavy as cassiterite. Often in fine, hair-like inclusions. Widelydistributed. Withquarta, feldspars, hematite, ilmenite, chlorite, brookite.
:y
B. UHERALS WITH HOIf-HETALUC LUSIXR
Streak — Pinl red, brown, or yellow
Name, Composition, and Referencea
Crystallisation Structure Crystals Massive
Luster
Transparency
CASSITEKITE Tetragonal Adamantine
C — Thick priematic ; knee- Dull SnO, or SnSnO, shaped twins quite Trauelucent to
common opaque
H — Compact, reniform, botryoidal, rounded Moses pebbles, often with
Kiaue, Daa, PareonB radial fibrous struc-
80, 344, 2*0 ture (wood Un)
Streak—Uncolored, vfbite, or light gray
Camallite
Orthorhombic
Vitreous
Reddish
C— Apparently hexago-
Dull
MgCl,.KC1.6H,0
nal, rare
Transparent to
lOfl. 323. 310
H — Compact, granular
translucent
Laumontite (Zeolite)
MonocUnic
DuD
Pink
H — Earthy, powdery
Opaque
Red
Ca(A1.20H).{Si,0>),.2H,0
*KAOLIHrrE (Kaolin)
Monoclinic
Dull
Reddish
C— Scaly, with hexago-
Pearly
H.Ali,0,
nal outline, rare
Opaque to
M— <;ompact, friable.
translucent
230, 481. 422
clay-Uke
♦ TALC, varieties
Monoclinic
Greasy
Reddish
FoliaUd
C— Thin tabular, indis-
Pearly
tinct
Translucent to
K— Foliated, globular.
opaque
fibrous, granular.
compact
227. 47fl. 421
Gypsuh
Monoclinic
Vitreous
Flesh red
C— Rare
Silky
Brick red
CaS0,.2H,O
M — Coarae, fine granular, Dull
fibrous, cleavable, Transparent to
sand opaque
:y
2. , RED, OR RED VIOLET HT COLOR Hardness over 3
Cleavage -C Fracture — F Tenacity
C — Indistinct F — Uneven Brittle
Specific Gravity
Recognized by liigh specific grav- ity. In veins cutting granite, gneiss; in alluvial deposits as stream tin. With quarta, wol- framite, scheelite, arsenopyrite, tourmaline, fiuorite, apatite.
Hardness 1 to 3
C — Indistinct F — Conchoidal Brittle
1. White C— Basal (scales)
2.6 YeUowish white F— Earthy, conspicu- Reddish white ous
Brittle
1. White C— Basal, perfect, con-
2.5 Reddish white spicuous when foli-
ated F — Uneven, splintery Sectile, lamise flexible
C — Clinopinacoidal, , perfect conspicu- ous; pyramidal, orthopinacoidal (crystals)
F — Conchoidal
Brittle, lamicuB flex-
Color due to henlatite or goethite. Bitter taste; absorbs moisture. With halite, kieserite, kainite, sylvite, anhydrite.
Harder when fresh and unexposed. In cavities and fissures in basic igneouB rocks. With stilbite, apophyllite, analcite, native copper.
Clay odor when breathed upon. Usually adheres to tongue and becomes plastic when moistened. Greasy feel. With quartz, feld- spar, corundum, diaspore.
Greasy or soapy feel important. FoluUed, easily separable, inelas- tic plates, H— 1; s'oapaione or steatite, coarse to fine granular, more or less impure, H up to 2 . 5. With serpentine, chlorite, dolo- mite, magnesite, actinolite.
Ferruginous gypsum. In lime- stones, shales. With halite, celes- tite, sulphur, aragonite, anhy- drite, ore deposits.
ible
:y
B. HIIfERALS WITH NOIT-BIETALLIC LUSTER
Streak— Uncolored, white, or gray
Name, CompositioQ, and EeferenceH
CryBtalliiatton
Structure
OryBtaU-C
MaBsive-M
Luster Transparency
Color
S;lvite Cubic
C— Cubes, alone or with KCl octahedron
Mosea M— Granular, compact KnoM. Diuu., PDB 98, 318, 310
Vitreous Transparent to
Red Yellowish red
HALITE (Rock salt) NaCI
Cubic
C— Cubes, often skeletal or hopper-shaped,
Transparent to translucent
Red Reddish
Purplish
M— Compact, cleavable, granular, fibrous, crusts, slalactitic
UpidoUte (Lithium mica)
Monoclinic
Pearly
Pink
C— Short prismatic
Translucent
Rose red
(Li,H).(F,OH)li,0,
M— Granular, coarse or fine; scales, cleavable
Red violet
2 Is, 487,
plates
GlAuberite
Monoclinic
Vitreous
Flesh red
C— Thick tabular
Greasy
Brick red
NaO.CaSO.
M— RenHorm, lamellar
Transparent to
132, S23,
Amorphous
Greasy
Brownish red
M— Irregular, stalactitic
Transparent to
Yellowish red
C,„H„0.
grains and lumps
translucent
290, 643.
3Sg
KalDite
Monoclinic
Vitreous
Flesh red
C— Tabular, prismatic,
Transparent to
Brick red
MgS0,.KC1.3H,0
154, 530,
M— Compact, fine gran- ular
translucent
Gibbaite (HydrargiUite)
Vitreous
Reddish
C— Tabular, pseudohex-
Pearly
A!(Oh),
agonai, rare
lary, surface smooth, internal structure
Translucent
92. 351,
fibrous
. Uncommon color.
ijGoogle
2. PnrE, RED, OR RED VIOLET Df COLOR Hsrdaess 1 to 3
Cleavage -C Fracture — F Tenacity
Characteristics find
C— Cubic F— Conchoidal Brittle
Color due to impurities. Salty bitter taste. May absorb mois- ture and become damp. Ueually in salt deposits. With halite, kainite, camallite.
White
C— Cubic, perfect, con-
Characteristic cubical cleavage and
spicuous F-Conchoidal Brittle
2,3
saline taste. Color due to im- purities. Hay absorb moisture and become damp. With shale, gypsum, anhydrite, polyhalite.
White
CBaaal, perfect
F— Scaly, granular Tough
ular limestone. In pegmatites, granites, gneisses. With red tourmaline (rubellite), amblyg- onite, spodumene, topaz.
White
C— Baaal, perfect
Bitter saline taste. On exposure
F — Conchoidal
becomes coated with white pow-
Brittle
dery crust. With halite, thenard- ite, mirabilite.
3.S
White
F— Conchoidal
Fossil resin. Electrified when
Brittle
1,1
rubbed. Often mottled and inclusions— insects, vegetable
remains, liquids, minerals.
White
C — Pinacoidal, pris-
Taste, salty, bitter, and astringent.
matic, not conspic-
Uoub
F— Uneven
2,2
Non-hygroscopic. With halite, sylvite.
Brittle
White
C — Basal, not conspic-
Strong clay odor when breathed
TouKh
upon. With bauxite, natrolite, limonite, corundum.
ijGoogle
B. HIWERALS WITH HOK -METALLIC LUSTER Streak — Uncolored, white, or light gray
CryHtUisation itioD, and Structure Lueter
ceB Crystals C Transparency
Massive
PHLOGOPrrE (Bronze n (K,H),Mg,AI(SiO,)a
ca) Monoclinic Pearly
C — Tabular, prismatic, Submetallic hexagonal or ortho- Transparent rhombic outline, translucent often large and coarse Mosea M — Plates, disseminated Pmon. scales
4ie
Copper red Bronze red Brownish red
*Cryolite
AlFj,3NaF
Vitreous Reddish
Greasy Brownish red
rare Transparent to Brick red
— Cleavable, granular translucent
BARITE (Heavy spar)
Calcite
CaCO,
Wulfenite PbMoO.
Uncommon color.
Orthorhombic Vitreous Reddish
C — Tabular, prismatic. Pearly Red
very common; crest- Transparent to
ed divergent groups opaque
M — Compact, lamellar,
fibrous, cleavable,
reniform
Hexagonal
Vitreous
Pink
C— Scalenohedral, rhom-
Dull
Red
bohedral, prismatic,
Transparent
Violet
tabular, often highly
to nearly
Amethystine
modified and
opaque
twinned
M— Cleavable, granular,
333 fibrous, compact
Tetragonal Greasy Orange red
C — Square, thin tabular, Adamantine Bright red
more rarely py- Transparent to
ramidal translucent M — Coarse to fine granu- lar
:y
2. Pirk, Red, Or Red Violet Dt Color
Cleavage — C Fracture — F Tenacity
Characteriatice and
C — Basal, perfect, con
spicuoua Tough, tamiiue very
elastic
When cleavage laminfe are held close to the eye in viewing a source of light, a star-like form is Bometimes observed. Especially characterletic of cryetalline lime- Btones, dolomites, Bchists. With pyroxenes, amphiboles, serpen-
White
C— Basal, prismatic,
perfect, nearly 90°,
siderite, chalcopyrite, galena, sphalerite, fluorite, columbite.
F— Uneven
Brittle
White
C— Basal, prismatic,
F— Uneven Brittle
Characterized by rather high specific gravity and cleavages. In metalliferous veins; pockets and lenticular masses in lime- stones. With galena, sphalerite, fluorite, chalcopyrite; manganese and iron minerals.
White
C— Rhombohedral,
perfect, very con-
spicuouB F— Conchoidal Brittle
2,7
Rhombohedral cleavage character- istic, especially on crystals. Cleavages often show stria tions. Very strong double refraction observed when transparent.
White C — Pyramidal, indis-
Yellowish white tinct
F — Conchoidal, uneven
Brittle
6.3 Square plates, sometimes with 7 . forms of the third order. With
lead minerals — galena, pyromor-
phite, vanadinite.
:y
BUHERALS WITH VOH-HETALLIC LUSTER Streak — Uncolored, white, or Ugbt gray
Crystallization Structure Crystals -C Massive— M
TranspareDcy
iranadialte Hexagooal Greasy Ruby red
C — Prismatic, small, at Translucent to Orange red I
Pb,Cl(VOj), times skeletal opaque Brownish red I
Kmua. Dana, PtuMog H— Compact, globular, 173, 600. 2M fibrous, Crusts
Streak— Uncotored, wUte, or light gray
Oibbdte (Hydrargillite)
Monoclinie
Vitreous
Reddish
Pearly
A](Oh),
agonal, rare H— Stalactitic, mammil- lary, surface smooth, internal structure
Translucent
92, 361,
360 fibrous
PolyhaHte
Monoclinie 7
Greasy
Flesh red
C— Indistinct
Pearly
Brick red
KgCa,(S0.)..2H,0
K--Compact, fibrous,
Translucent
163. 635.
lamellar
Aithydrite
Orthorhombic
Vitreous
Reddish
C— Thick tabular, pris-
Pearly
Brick red
CaSO,
matic, rare
Translucent to
H— Granular, compact,
opaque
fibrous, lamellar.
133. 629.
327 cleavable
Celestite
Orthorhombic
Vitreous
Reddish
C— Tabular, prismatic.
Pearly
Brick red
SrSO,
common
Transparent to
M — Compact, cleavable.
translucent
fibrous, granular.
134, 628,
321 reniform
*BARITB (Heavy spar)
Orthorhombic Vitreous
C — Tabular, prismatic, Pearly
very common; crest- Transparent
ed divergent groups opaque
M — Compact, lamellar,
fibrous, cleavable,
reniform
:y
3. PniK, RED, OR RED VIOLET IN COLOR HardncM 1 to 3
Cleavage -C Fracture -F Tenacity
hit
C— None
ello
wish white F— Conch oidal, unev
en 7.2
Brittle
Crystal faces smooth with sharp edges. With lead minerals but never in large quantities.
C— Basal, 1
uous Tough
Strong clay odor when breathed upon. With t>Buxitc, natrolite, limonite, corundum.
White P— Stalky,
Reddish white Brittle Yellowish white
Taste, bitter and astringent, but weak. With halite, anhydrite,
2.8 Granular
sometimes conspic-
reaemble mar- ble. Not as heavy aa celestite or barite. In limestones, shales. With halite, gypsum.
C — Basal, prismatic,
conspicuous F— Uneven Brittle
Heavier than calcitc, anhydrite; lighter than barite. In lime- stones, dolomites, shales. With gypsum, aragonite, halite, galena, sphalerite.
C — Prismatic,
spicuous F — Uneven Brittle
Characterized by rather high specific gravity and cleavages. In metalliferous veins; pockets and lenticular masses in lime- stones. With galena, sphalerite, fluorite, chalcopyrite; manganese and iron minerals.
jyGoogle
B. boherals with noh-hetaluc lusir
streak— Uncolored, wMte, or Ught gray
Crystallization Structure Crystals— C Massive - M
Transparency
i STILBITE (Desmine)
(Ca,Na,)Ali,0,..8H,0
Monoclinic Vitreous Pale red
C— Twinned in sheaf-like. Pearly Brick red
radial, or globular Tranaparent to aggregates translucent
glH.CaA!,(SiO0..3H,O
a ' 281. 4M. 414
I Laumontite
;'Ca(A1.20H),(ai,0,)j,2H,0
Monoclinic Vitreous Flesh red
C — Tabular, striated Pearly Brick red M — Foliated, granular, Transparent to
globular translucent
Monoclinic Vitreous Pink
C~Columnar Dull Red
H— Radial, divergent. Transparent to
earthy opaque
SERPEHTIHE H,Mgi,0,
228. 476,
Lpidolit {Lithium mica)
(Li,H)j(F,0H)5AIi,0,
219. 4B7.
Hargarite
H,CaA]i,0„
221. 470.
'DOLOHirE
CaMg(CO,),
357, 338
Orthorhombic ? Greasy Brownish red
C — Unknown Waxy Red
H — Compact, columnar, Translucent to
fibrous, lamellar, opaque granular
Monoclinic Pearly Pink
C — Short prismatic Translucent Rose red
H — Granular, coarse or Red violet
fine; scales, cleavable plates
Monoclinic Pearly Pink
C — Six-sided scales. Vitreous Rose red
plates Translucent M— Scaly, foliated, gran- Hexagonal Vitreous Pink C — Rhombohedral with Transparent to Reddish
curved surfaces translucent M — Coarsely crystaUine,
compact, granular,
Uncommon color.
ijGoogle
S. PDIK, RED, OR RED VIOUTT Df COUIR
Cleavage — C Fracture — F Tenacity
Specific Gravity
Characteristic and Associates
C — Pinacoidal
F — Uaeven Brittle
Radial and sheaf -like structure important. In basic igneous rocks, ore deposits. With chab- azite, apopbylUte, heulandite, datoUte, calcite.
C — Clinopi oaooidat ,
F — Uneven Brittle
C — Clinopinacoida 1,
prisroatic F — Uneven, earthy Brittle, friable
F— Conchoidal, splin
tery Brittle
In basic igneous rocks and metal- liferous veins. With chabasite, stilbite, apophyllite, datolite.
On exposure becomes dull and crumbles to powder. In cavities and fissures in basic igneous rocks. With stilbite, apophyl- lite, analcite, native copper, epidote.
Smooth and greasy feel. Often spotted, clouded, multicolored.' Color due to unusual amount of ferric oxide. With maguesite, calcite, chromlte, gamierite, pyrope, platinum.
C— Basal, perfect
2,8
When massive often resembles
F— Scaly, granular
granular limestone. In pegma-
Tough
tites, granites, gneisses. With red tourmaline (rubellite), am-
blygonite, spodumene, topaz.
C— Basal, perfect, eon
3,
Resembles the micas in structure
and cleavage, but harder, lamin
F— Scaly, granular
brittle and inelastic. With
Brittle
chlorite, corundum, emery, dia- spore.
Crystals generally curved or sad-
perfect
dle-shaped. Marble includes
F— Conchoidal
some compact varieties. In in-
Brittle
dependent beds; fissures, and cavities; with ore deposits.
.jGoogle
B. HinERALS WITH VOH-KETALLIC LUSTER
Streak
-Uncoloreil, white, or Uht gray
Crystallization
Name, Composition,
and
Structure
Luster
Reference!,
Crystals Massive -M
Transparency
Aragohite
Orthorhombic
Vitreous
Reddish
C— Chisel- or spear-shap-
Greasy
Brick red
CaCO,
u™
ed; pseudohexagonal prisms ; radial, co- lumnar or aeicular
Transparent to translucent
M— Stalactitic, renitorm,
119. 361,
crusts, oolitic
Sphalerite
Cubic
Greasy
Brownish red
C— Tetrahedral, common
Submetallic
YeUowish red
ZnS
M-Cleavable, fine or
opaque
33. 2S1.
pact
Hexagonal
Vitreous
Rose red
C— Rhombohedral, rare
Brownish red
MnCO,
H — Cleavable, granular, compact, botryoidal.
Pink
118, 350.
crusts "ciTbic
Vitreous
PLUORITE (Fluor spar)
Red violet
C— Cubes, alone or modi-
Transparent
Pink
CaF,
fied, well developed, common; penetra- tion twins M— Cleavable, granular,
to nearly
opaque
Rose red
103, 330,
fibrous
1 *CHABAZrTE
Hexagonal
Vitreous
Flesh red
C— Rhombohedral, cube-
Translucent to
Red
CaA]i,0„.8H,0
etc.
like, lenticular
transparent
I *Haimotome
BaAli,0„.6H,0, etc.
Monoclinic C— Usually t trating a
Vitreous , pene- Translucent
Xenotime YPO.
Tetragonal Greasy Flesh red
C — Pyramidal, prismatic Vitreous Brownish red
H — Compact, dissemi- Translucent to Yellowish red
nated, rolled grains opaque
:y
2. PINK, RED, OR RED VIOLET IH COLOR Hardneu 8 to 6
Cleavage — C Fracture -F Tenacity
White Gray
C— Brachypinacoida) ,
prismatic F — Conch oidal Brittle
Gray Yellowish white
C— Dodecahedral, perfect, usually
F~Conchoidal
Brittle
White
perfect, conapicu-
F— Uneven Brittle
White
C— Octahedral, per-
Brittle
' Twins common, often pseudo-
hesagonal (prism and striated base). In cracks and cavities, disseminated; with ore deposits; deposition from hot springs; in shells. With gypsum, celestite, sulphur, siderite, leolites.
Color and streak vary with im- purities. Extensively in lime- stones. With galena, chalcopy- rite, pyrite, barite, fluorite, rho- dochrosite.
May turn brown to black on ex- posure, due to MnO,. With galena, sphalerite, pyrite, alaban- diie, rhodonite, psilomelane, silver ntinerals.
Easily recognized by crystal form, cleavage, and hardness. Com- mon gangue mineral of metallic ores. With galeoa, sphalerite, cassiterite. calcite, quartz, barite.
C— Rhombohedral, not conspicuous F— Uneven
Brittle
C — Pinacoidal F— Uneven Brittle
Yellowish white Brownish white Reddish white
C — Prismatic
F — Uneven, splintery
Brittle
Generally in cube-Uke crystals. Inferior cleavage distinguishes it from fluorite and calcite. In basic igneous rocks. With anal- cite, stilbite, harmotome, heu- landite.
Cruciform twins. In basic igneous rocks and metalliferous veins. With chabasite, calcite, adularia, quartz. Pkillipaiie, contains calcium replacing barium.
Commonly as loose, disseminated, or attached crystals resembling zircon, but softer. In granite, gneiss. With zircon; alluvial deposits.
.jGoogle
B. HmERALS WITH flOK-HETALLIC LUSTER
Streak — Uncolored, white, or light gray
Crystallization Structure Crystals -C
Luster TranHparency
Tetragonal Adamantine
C— Pyramidal, small; Greasy
tabular Transparent to MoH H — Druay crusts, reni- translucent
Kmus. Daoa. Panoiis form, granular, dis-
139, 540, 33S seminated, compact
APOPHYLLITE (Zeolite) Hi.Ka,(8iO,)„.9H,0
Tetragonal Vitreous
C — Prismatic, pyramidal. Pearly
paeudocubical, tabu- Transparent lar to nearly
H— Lamellar, granular, opaque compact
Pale red Flesh red Rose red
Wollastonite, (Pyroxene, tabu- Monoclinic Vitreous Reddish
lar spar) C — Tabular, prismatic . Silky
CaSiO, H — Cleavable, fibrous, Transparent to
granular, compact translucent
Apatite
Hexagonal
Greasy Viole
C~Prismatic, thick tabu-
Vitreous Brow
Ca(PO.).
Translucent to Red
times large with
opaque
rounded edges
M— Compact, fibrous,
nodular, reniform
170,
497,
Huebnerite
Monoclinic
Resinous Brow
C— Long fibrous, bladed,
Submetallic
MnWO.
stalky; often diver-
gent, without good
opaque
M— Compact, lamellar,
140,
granular
ijGooglc
3. Pihk, Red, Or Red Vioit Ih Color
Hardness 3 to 6
Cleavage 'C Fracture ""F Tenacity
C — Pyramidal F— Conchoidal, Brittle
Small, well developed octahedral- like crystals, ueually on quartz; when massive, high specific gravity important. With wol- framite, caasiterite, fluorite, topaz, molybdenite.
4.6 White
C — Basal, perfect,
apicuouB F — Uneven
Brittle
Prism faces vertically striated. In fissures and cavities in basic igneous rocks. With natrolite, analcite, laumontite, datolite, pectolite, native copper, calcite.
C — Basal, orthopina-
coidal F— Uneven
Brittle
Fibers may be parallel or divergent. Typical contact mineral. Often in crystalline limestone, with gar- net, dioside, vesuvianite, epidote, graphite.
C — Basal, imperfect F— Conchoidal, uneve:
Brittle
Crystals may be vertically striated and have fused appearance. Color often unevenly distributed, — mottled brown and green. In crystalline limestones, metallif- erous ore deposits, igneous rocks. With quartz, cassiterite, fluorite, wolframite, magnetite.
4.6 Greenish gray
C — Clinopinacoidal , perfect, conspicu-
Structure, cleavage, and specific gravity characteristic. In quartz veins. With wolframite, fluorite, pyrite, scheelite, galena, tetrahe-
:yGoogle
B. MniERAi WITH hou-hetallic luster
Streak — Uncokired, white, or gnj
CiystalliEation
Name, Composition, and
Structure
LuBfer
References
Crystals -C Massive -M
Transparency
"Ahalcite
Cubic
Vitreous
Reddish
C— Tetragonal trisocta-
Translucent to
Brick red
Na,Al,{Si0,).,2H,O
hedrons, cubes
Moeea
H — Granular, compact
EnuB, Duu. Panon
279, 460. 415
HatroHte
Orthorhombic
Vitreous
Reddish
C— Slender prismatic,
Silky
Na,Al(A10)(SiO,),.2H,0
nearly square, radial
Transparent to
or interlacing groups
MFibrouB, granular,
277. 1. 416
compact
Thom80ii!te
Orthorhombic
C— Prismatic, vertically
Vitreous
Silky
Reddish
2{Ca,NaAU(SiO,),.-
striated, divergent
Pearly
5H,0
groups H — Fibrous, columnar, radial; spherical con-
Translucent to transparent
276. 482. 418
cretions
DatoUte
Ca(B.OH)SiO.
MoDOclinic
M — Compact, fibrous, granular, botryoidal
Vitreous Pink
Greasy Red
Dull Red violet
Translucent to opaque
TITAHITE (Sphene) CaTiSiO,
Monoclinie Vitreous
C — Wedge- or envelope- Greasy
shaped when dissem- Transparent inated; tabular or opaque
prismatic when at- tached H — Compact, lamellar
Monoclinie Resinous Hyacinth red
C — Thick tabular, square Vitreous Brownish red
prismatic Translucent to
H — Angular, rolled opaque
:y
3. Pink, Red, Or Red Violet Ir Color
Hardness 3 to S
Cleavage — C Fracture -F Tenacity
C — None
F— Uneven, conchoid-
C — Priematic F — Uneven Brittle
Good cryetala common. In fis- sures and cavities in basic igneous rocks. With apophyllite, chaba- site, natrolite, laumontite, dato- lite, native copper, prehnite, epidote.
Crystals have nearly square cross- section. With chabazite, anal- cite, apophyllite, stilbite, prehn- ite, datolite.
C — Pioacoidal
F— Uneven Brittle
When massive, radial fibrous, often mottled or banded. In fissures and cavities in basic igneous rocks. With stilbite, analcite, prehnite, calcite.
6. White 5.6 Gray
C — Priamatic, con- spicuous parting often noted
F— Conchoidal
Brittle
Compact masses often with brownish, yellowish, or whitish streaks and spots. In cracks and cavities in basic igneous rocks. With calcite, prehnite, epidote, native copper, zeolites.
With feldspars, pyroxenes, amp hi- boles, chlorite, scapolite, zircon.
Crystals commonly small, highly
modified, or as rolled grains in sand. With magnetite, lircon, garnet, thorite, gold, chromite, diamond.
:y
B. mifBRALS WITH HOH-CBTALLIC lusier Streak— Uncolorcd, white, or Ut gray
CryetaUiiation Structure CryBtals -C MaBsive— M
TranspareDcf
C — Dodecahedrons Na,Al,{AICl)(8i04), M— Compact, diBsemi-
MoKB Dated grains, nodular
233,
'Cancrinite Hexagonal
C — Prisma tie, rare H,(Na„Ca)j{NaCO,)li,0„ M— Compact, lameUar, columnar, dissemi- 333, 411. 395 nated
HEPHELITE (Nepheline, Hexagonal
elaeolite) C— Short prismatic, {Na,K),AI,Si,0,. tabular
M — Compact, dissemi- nated grains
332. 409, 39S
SCAPOLTTE (Wer
irite)
/ nNaAli,0„Cl
Tetragonal C — Prismatic H — Compact, granular fibrous, columnar
Vitreous Pink
Greasy Reddish
Transparent to translucent
Greasy Reddish
Vitreous Rose red
Traospareat to translucent
Greasy Reddish
Vitreous Brownish red
Transparent to Brick red opaque
Vitreous Pink
Greasy Red violet
Translucent Brick red
TremoUte (Amphibole), variety Monoctinic
Hexagonite C — Bladed, without CaMg,(8iO,)i
Rbodonite (Pyroxene)
*Willemite (Trooatite)
terminations H — Compact, columnar,
fibrous Triclinic C — Tabular, prismatic,
rounded edges, often
H — Compact, cleavable, granular, dissemi- nated grains
Hexagonal
C— Prismatic
M— <mpaet, granular, disseminated grains
Vitreous Pink
Silky Red violet
Transparent to Lavender translucent
Vitreous Brownish red
DuU Flesh red
Transparent to Rose red opaque
Greasy Fle red
Vitreous Brownish red
Transparent to
opaque
:y
2. PIHK, RED, OR RED VIOLET llf COLOR Hardness 3 to 6
C — Dodecahedral F — Conchoids 1, un
Characteristics and
Recognized by associates — neph- elite, cancrinite, leucite, feldspar, zircon; not with quartz.
C— Prismatic, perfect F— Uneven Brittle
Typical associates — nephelite, Bodalite, biotite, feldspar, titanite.
C — Prismatic, not
conspicuous F— Conchoidal Brittle
C — Prismatic, perfect, conspicuous — 124° Brittle
Distinguished from orthoclase by interior cleavage, and more greasy luster. With feldspars, cancrinite, biotite, Bodalite, zir- con, leucite, corundum; not with
Often resembles pink fluorite in color, but cleavage less distinct, and harder. In metamorphic rocks, especially gi'snuiar lime- stones. With pyroxenes, apa- tite, garnet, titanite, biotite, amphiboles.
Silky luster and distinct cleavage {124°) important. In limestones, dolmites; also schists.
Tough, when
crystals brittle
May be stained brown to black on exposure, FowlerUe, variety containing zinc. With Irank- linite, zincite, willemite, calcite, tetrahedrite.
C — Basal, prismatic F — Uneven Brittle
Crystals of willemite small, those of Iroostite — manga nifero us va- riety — often large. Character- ized by associates — franklinite, z incite, rhodonite, calcite.
:y
B. HIHERALS WITH ROn-HETALLIC LUSTER
Streak— Uncolored, white, o
light gr.y
Name, Compoeition,
and
Crystalliuation Structure CryBtala -C Massive -M
Luster Transparency
Color
OPAL, varieties
Fire opal Opal jasper SiO,.xH,0
Amorphous Vitreous M— Renifonn,botryoidftl, Greasy
stalactitic, compact Transparent to opaque
sad
Red Brownish red
Streak— Dncolored, white, or light gray
ORTHOCLASE (Feldspar) KAtSijO,
260, 370, 378
Chondrodite
[Mg(F,OH)LMg,(SiO0
Ca,Al,(AI.OH)(SiO,),
199. 437, 40e
EPmOTE
Ca,(Ale),(A1.0H)(SiO.),
200, 43S, 409
Rutile
TiOj or TiTiO.
Monoclinic
C — Prismatic, thick tabular; twins; often large
H — Cleavable, granular, disseminated
Monoclinic
C — Small, highly modi- fied, rare
M — Rounded, dissemi- nated grains; com-
Orthorhombic
C — Prismatic, deeply striated, bent, with- out good termination
M — Columnar, broad bladed, fibrous
Monoclinic
H — Columnar, fibrous, parallel and diver- gent; granular
Tetragonal
C — Prismatic, vertically striated; twinned, yielding knee-shaped or rosette forms
M — Compact, dissemi-
Vitreous Flesh red
Pearly Brick red
Translucent to opaque
Vitreous Brownish red
Greasy Dark red
Translucent to
opaque
Vitreous Red
Transparent to opaque
Adamantine Dark red Submetallic Brownish red
Translucent to opaque
:y
a. PIHK, RED, OR RED VIOLET IH COLOR Hardness 3 to 6
Cleavage — C Fracture -F Tenacity
Specific
Gravity
White
F— Conchoidal
spicuous Brittle
Structure and fracture character- istic. Fire opal, transparent to translucent and red; opal jatper, greasy and opaque, resembling jaeper. In veins, cavities, and masBea of irregular outline.
C — Basal, clinopina- coidal, perfect, conapiouo us — 90°
F — Conchoidal, un-
Brittle
C— Basal
F — Conchoidal, i
Characterized by rectangular cleavage and absence of twinning striations. In granitic rocks. With quartz, other feldspars, mica, hornblende, zircon.
Associates important. Chiefly in crystalline limestones and dolo- mites. With spinel, i pyroxenes, magnetite, i
White
conspicuous F— Uneven Brittle
broken, columnar masses. In crystalline schists. With horn- blende, vesuvianite, epidote, gar- net, feldspars.
White
C— Basal, perfect
With quartz, feldspar, garnet.
T.
Grayish
F— Uneven
Brittle
vesuvianite, hornblende, pyrox- ene, magnetite.
Gray
C — Prismatic, py-
Not as heavy as cassiterite. Often
Yellowish white
ramidal, not
as fine hair-like inclusions.
Bro¥mish white
conspicuous F— Uneven Brittle
Widely distributed. With ite, chlorite, brookite.
ijGoogIc
B. Hiherals With Hok-Hetaluc Luster
Streak — Uncolored, white, or Ught gray
Name, Composition, and Referencea
Cryatallization Structure Oystala-C Massive— M
Luster Traosparency
Cassiterite
Dans. PuBODB
Tetragonal C— Thick prismatic; knee-shaped twins
H — Compact, reniform, botryoidal, rounded pebbles, often with internal, radial fibrous structure, tvood tin
Adamantine Resinous DuU Translucent to
opaque
AflDALUSITE
AUSiO,
Orthorhombic Vitreous Pink
C — Prismatic, rough. Dull Rose red
nearly square, often Translucent to Red violet
large and without opaque
—Columnar, fibrous, granular, dlssemi-
♦Olivihe
(Mg,Fe),SiO
Orthorhombic
C — Prigmatic, thick
tabular H — Rounded, dissemi- nated glassy grains; granular aggregates
Vitreous Brownish red
Dull Yellowish red
Translucent to
transparent
GARIfET, varieties
GrossTilaTtte R,"R,'"(SiOi), Pyrope R" =Ca,Fe,Mg SpessarltU R'" Al,Pe AlmaTtdiU
AndradiU
—Dodecahedrons, te- tragonal trisoctahe- drons, alone or in combination
—Granular, compact, lamellar, dissemi- nated, sand
Vitreous Rose red
Transparent to Ruby red opaque Brownish red
Dark red
:y
a. PIHE, KED, OR SED VIOLET U COLOR
Hardneis over 6
Cleavage — G Fracture -F
Tenacity
Charactri8tics and
White C— Indistinct
Yellowish white F — Uneven Brownish white Brittle
Distinguished by high specific gravity. In veins cutting gran- ite, gneiss; in alluvial deposits as stream tin. With quarts, wolfram- ite, echeelite, arsenopyrite, tourmaline, fluorite.
C — Prismatic F— Uneven Brittle
Due to alteration, surface may be covered with scales of mica and, hence, is softer. In metamorphic rocks often as rounded or knotty projections. With cyanite, sil- limanite, garnet, tourmaline.
White C— Pinacoidal
Brownish white F — Conchoidal Yellowish white Brittle
In basic igneous rocks — basalts, traps; crystalline limestones. With augite, magnetite, spinel, plagioclase, chromite, pyrope.
White
C— Dodeeahedra!
7J
Gray
distinct F — Conchoidal, u
Grossttlarile, in crystalline lime- stones and dolomites, with wol- lastonite, veauvianite, diopside, scapolite; pyrope, rounded grains, in serpentine; apessarlite, in granitic rocks, with topaz, tour- maline, quartz, orthoclase; almandile, with mica, staurolite, andalusite, cyanite; andradUe, with magnetite, epidote, feld- spar, nephelite, leucite.
:y
B. mnERALS WITH HOIf-HETALLIC LUSTER
Streak
— Uncolored, white, or Ught gray
Name, Composition, and Referenoee
Crystallisation Structure Cryatals-C Massive
Luster Transparency
Color
QUARTZ, Phanerocrystalline
varieties
Hexagonal
C — Prismatic, horizon-
Vitreous Greasy
Red violet Rose red
SiO, Amethyst Rose quartz Aventurine
tally striated, com- H — Compact, eranular
Transparent to
opaque
Brick red Brownish red
Cryptocryatalline
varieties
Hexagonal
C— Never in crystals
Waxy Vitreous
Bright red Dark red
Corneiian
M— Banded, spotted.
Translucent to
Brownish red
Agaie Sardonyx Jaxper Heliolrove
compact
opaque
Clastic varieties Hexagonal
Sand Loose or strongly co Sandstone soUdated grains
QuarUUe fragments
and Kraiu. Daan. Psnuns
Dull Brownish red
Translucent to Purplish red opaque
TOURKALISE, variety
HiibelliU M,'Al,(B.OH),Si,0„ M'-Na,K,Li,Mg,Fe
Hexagonal
C — Prismatic, often vertically striated, rarely with good terminations
H — Divergent, columnar, compact
'Spodumene (Pyroxene), Monoclinic
variety C— Prismatic, tabular,
LiAl(SiOt)3 KumUt sometimes large
M — Cleavable, broad columnar
247,
3 Is
Hexagonal
C — Rhombohedral, py- ramidal, lenticular, highly modified
Vitreous Pink
Transparent to Rose red translucent Ruby red
Vitreous
Transparent
Vitreous Rose red
Transparent to translucent
:y
i. phik, red, or red violet in color
Cleavage - G Fracture -F
Tenacity
C Indistinct
F — Conchoidal, i BpicuouB
C — Indistinct F — Conchoidal, c
Specific Gravity
Characteric coachoidai Cracture and glassy luster. Amethyat, usually in cryatals, purple or blue violet; rose qtiartz, usually mass- ive, pink to rose red; aventurine, massive and glistening, due to included scales; ferruginous quarls, colored by iron oxide.
Not as glassy as phancrocrystal- liae varieties. Camelia-a, jasper, uniform in color; agate, sardonyx, banded; heliotrope, spotted. To distinguish, see references.
C — Indistinct F — Uneven Brittle to tough
Figment is usually ferruginous matter. Sand, loose, unconsoli- dated grains; sandelone, consoli- dated sand; quartzite, metamor- phosed sandstone.
F — Conchoidal,
Spherical. triangular cross-section Often with lonal distributi color — red, green, colorless. Frequently as long, divergent, columnar masses imbedded in lepidolite.
of
—Prismatic, perfect; pinacoidal part-
F — Uneven, conchoid- al Brittle
C — Prismatic, indis-
F — Conchoidal Brittle
Commonly in broad plates, due to distinct pinacoidal parting. Prism angle 93°. In granitic rocks. With tourmaline, tepido- lite, beryl.
Distinguished from quartz and topaz by crystal form and cleav- age. In pegmatites and meta- morphic rocks. With quarts, topaz, beryl, amaionatone, chrysoberyl.
JyGoOgIc
imiERALS WITH n05-H£TALLfC LUSTER Streak — Uncolored, white, or light gray
CrystBllizatioQ Structure Crystals -C Massive— M
Transparency
Tetragonal Adamantine
C — Prismatic, pyramidal, Vitreous
small, well developed Resinous
Hosea H — Irregular lumps. Transparent tc
Panons grains opaque
Brownish red
Dark red
Al,(F,OH)iO.
Orthorhombic Vitreous Pink
C — Prismatic, vertically Transparent to Red
striated, highly opaque Red violet
modified M — Compact, granular,
rounded fragments
SPINEL, varieties
Balas R"(R"'0,), Ruby R"-Mg,Fe,Mn Rabicetie R'" — AI,Fe AlmaTidine
Vitreous Deep red
Splendent Rose red
Transparent to Orange red
translucent Bluish red
ISe. 338. 34
COROHDUH, varieties Ruby A1,0, Oriental
amethyst Common
Hexagonal
C — Prismatic, tabular,
pyramidal, rhombo-
hedral H — Compact, granular,
lamellar
Vitreous Pink
Transparent to Red translucent Red violet
:y
2. Piitk, K£D, Or Red Violet In Color
Hardness over 6
Cleavage - Fracture — Tenacity
, White
C— Indistinct F— Uneven Brittle
White
C— Basal, perfect, usually conspicu-
Brittle
C-Octahedral, iodis-
F— Conchoidal
Brittle
C — None. Nearly rectangular basal and rhombohedral partings, conspic- uous; often stri- ated
F — Conchoidal
Brittle to tough
Often in the more acid igneoiu rocks — granites, syenites; allu- vial deposits, with gold, spinel, corundum, garnet. Hyacinth, dear and transparent.
Crystals usually developed on one end only. Massive varieties dis- tinguished from quartz by greatr hardness, higher specific gravity, and basal cleavage. Color may fade on exposure. In veins and cavities in granitic rocks; alluvial deposits. With cassiterite, tourmaline, fluorite, beryl, scheel- ite, wolframite.
Balat spinel, rose red; ruby spinel, deep red; rubiceUe, yellow to orange red; almandine, bluish red. Usually in precious stone placers, with lircoa, garnet, mag- netite; more rarely as contact mineral in crjrstalline limestones.
When massive often multi-colored -r-blue, green, gray, iiuin/, trans- parent, red; oriental amethyst, violet. In limestones, granites, , peridotites, alluvial de- posits. With magnetite, hema- tite, nephelite, mica, spinel.
jyGoogle
B. HinERALS WITH HOB-HETAIXIC LUSTER
Streak— Blue, green, brown, yellow, or black
Name, Composition, and
Crystallization Structure
Crystals -C Massive -M
Transparency
Glaoconitb reKSi,0,.H,0 T
Honoclinic 7 H — Sand, earthy, dis- seminated
Dull
Opaque
Dark green Light green
Monoclinic
Pearly
Grass green
ntel
C— Tabular, eix-sided.
Vitreous
Brownish
H.Mg.Ali.O,. 7
often bent and
DuU
twisted
Translucent to
Bladdsh green
M— Foliated, scaly.
opaque
223. 473,
granular, earthy
Amiaberglte (Nickel bloom)
Monoclinic
Dull
Apple green
C — Hair-like, indistinct,
Vitreous
Light green
Ni,(AsOJ,,8H,0
179. 509.
rare M— Earthy, crusts, stains
Opaque to translucent
Vinasite
re,(P0.),.8H,0
178, Sos. 223
Monoclinic
C — Prismatic, tabular — Reniform, globular, with radial fibrous structure; earthy
Vitreous Indigo blue
Dull Bluish green
Transparent to Blaoldsh opaque green
Covellito
Hexagonal
Indigo blue
C— Tabular, rare
Resinous
Blue black
CuS
M — Compact, granular,
Opaque
fii.
iS3 crusts
CluTBOColla H,CuSi0..H,0
Gamierite
H,(Ni,Mg)8iO,
Amorphous 7
M— Compact, reniform,
incrustations, seams, stains, earthy
Vitreous Greasy Dull Translucent to
opaque
Green Greenish
blue Blue
Amorphous 7 , H— Compact, reniform, earthy
Dull
Greasy Opaque
Pale green Apple green Emerald green
.jGoogIc
3. Greeit, Blue, Or Blue Violet In Color
Hardness 1 to 3
Cleavage — C Fracture -F Tenacity
Characteriatica and
1, Light green
Commonly as green sand. Resem- bles earthy chlorite. Dissemi- nated in aandatones, limestonee, and marl.
1. Pale green
conspicuouH F — Scaly, earthy Tough to brittle
—Earthy
Lamina are flexible but inelastic, with slightly soapy feel. Com- mon in schists and serpentine. With magnetite, garnet, diopside, magnesite. Often as a scaly or dusty coating on other minerals, Pseudomorphous after garnet.
Common alteration product of nickel-arsenic minerals. With niccolite, chloanthite, calcite.
C — Clinopinacoidal F — Fibrous, earthy Sectile, thin laminse flexible
UsuaUy massive. Color and streak darken on exposure. In clay, peat, bones, shells. With limonite, pyrrhotite, pyrite.
F— Uneven Thin plates a
Characteristic blue color. With , chalcopyrite, bomite, chalcocite.
2. Pale green
C— None
F — Conchoidal.
earthy Brittle
2 . Usually recognized by enamel-
2.2 like appearance, conchoidal frac- ture, and non-fibrous structure. When impure brownish or black- ish. With copper minerals — malachite, aaurite, chalcopyrite.
2.3 Often as rounded, pea-shaped 2 . 8 masses with vamish-like sur- faces and earthy interior. Fre- quently adheres to tongue. With olivine, serpentine, chromite,
.jGoogIc
B. HINBRALS WITH HOIT-HETALLIC LUSTER Streak— Blue, green, brown, yellow, or black
Cryetallwation
Name, Compositioa, and
Structure
References
Cryetale -C
Massive -M
Transparency
Chalcanthite (Blue vitriol) CuS0,.5H,0
KrauB, Dana, 151. 534,
Mose
pi
Triclinie
C— Tabular, amall, rare M— Crusts, reniform, Btalactitic, powdery
Vitreous
Dull
Translucent
Deep blue Sky blue Greenish blue
ZaRatite
NiCO, 2Ni(OH),.4H,0
128, 367,
K — Fine, crystalline,
warty crusts; rarely compact
Vitreous Transparent to translucent
Emerald green
Olivenite Cu(Cu OH)AbO,
17S, 504,
Orthorhombic
C— Prismatic, acioular
M— Reniform, fibrous,
with velvety surface;
earthy
Vitreous Transparent to
opaque
Light green Olive green Blackish gree
Streak— Bine, green, brown, yellow, or black
Atacamite
Orthorhombic
Vitreous
Bright green
C —Slender prismatic, usu
Adamantine
Emerald green
Cu(OH)Cl.Cu(OH),
ally in confused
Transparent
Blackish green
fibrous aggregates
to nearly
M— Granular, compact,
opaque
108. 322,
288 crusts
Chrygocolla
Amorphous 7
Vitreous
Green
M— Compact, reniform,
Greasy
Greenish blue
HuSiO,.H,0
incrustations, seams,
Dull
Blue
stains, earthy Translucent to
opaque
Brochantite
CuSO.,3Cu(OH),
Orthorhombic Vitreous Emerald g
C — Prismatic, acicular. Pearly Blackish
vertically striated Transparent to green M— -Reniform, fibrous, translucent
:y
3. Greeh, Blue, Or Blue Violet Dt Color
Cleavage — C Fracture -F Tenacity
Specific Gravity
CharacteristicB and Associates
C — Indistinct
F — Conchoidal Brittle
Disagreeable metallic taste. Oxi- dation product of copper sul- phide minerals. With chalco- pyrite, bornite, melanterite, pyrite, goslarite
Ab crusts on, or veinlets in chro- mite, niekeliferous magnetite, associated with serpentine.
Divergent, fibrous structure and velvety surface important. With coppter minerals. Not as B malachite.
Hardness over 3
3. Apple green
C — Brachypinacoidal F— Conchoidal
Brittle
With other copper minerals; also limonite, hematite. Not as com- mon as malachite.
C — Brachypinacoidal
F — Uneven Brittle
Usually recognized by enamel- Lke appearance, conchoidal frac- ture, and non-fibrous structure. When impure brownish or black- ish. With copper minerals — malachite, azurite, chalcopyrite.
Not as common as malachite. Secondary copper mineral. With malachite, azurite, cuprite, chal- copyrite, limonite.
:y
B. mifERALS WITH hou-icetallic luster
Streak — Blue, green, brown, Tellow, or black
Crystallization Structure Crystals Missive "-H
Luster Transparency
Azorite
2CuC0,.Cu(0H),
Halachite
CuCO,,0u(OH),
PYROMORPBITE Pb.CI(PO.),
Dioptase
211, 424
Lazurite (Lapis lazuli)
Monoclinic Vitreous Azure blue
C — Short prismatic, tab- Dull Dark blue
ular, often in spher- Translucent to ical aggregates opaque
M — Fibrous; botryoidal, I with velvety or
,g radial structure; earthy, crusts
Monoclinic
C — Acicular, often in
groups or tuffs M — Fibrous; atalactitic, botryoidal, with smooth surface and in- ternal banded or radial fibrous structure; vel- vety crusts, earthy
Hexagonal Greasy
C — Prismatic, thick tab- Adamantine
ular, rounded and Translucent
barrel-shaped opaque H — Globular, reniform, diaseminated, crusts
Silky Emerald
Adamantine green
Duli Grass green
Translucent to Dark green opaque
Dark green Emerald green
Yellowish
(Na„Ca),AUAl(NaSO„NaS„ Cl)](SiO,),
Hexagonal C— Prismatic, Mmall, highly modified M — Crystalline crusts
C — Dodecahedrons, rari H — Compaot, irregular
Vitreous Emerald Transparent to green
opaque Dark green
Vitreous Azure blue
Translucent to Violet opaque blue
Greenish blue
HORIfBLEIfDE (Amphibole) Silicate of Ca, Mg, Fe, Al, eti
Monoclinic
CLong prismatic, prism angle 124°; often with rhombohedral- like terminations
H — Bladed, fibrous, gran- ular, compact
Vitreous Blackish
Silky green
Translucent to Dark green opaque
:y
3. Greer, Blue, Or Blue Violet Is Color
Cleavage Fracture -F
Tenacity
C — Domatic F — Conchoidal Brittle
Common alteration product of copper minerals. With mala- cliite, cuprite, native copper, chalcocite, chalcopyrite, bomite. Pseudomorphous after cuprite, tetrahedrite. Alters to mala-
C — Basal, pinacoidal F — Conchoidal, splin- tery Brittle
Very common alteration product of copper minerals. With azu- rite, cuprite, native copper, chalcocite, chalcopyrite, bomite. Pseudomorphous after cuprite, azurite, native copper. Surface may be almost black, due to the oxide, melaconite.
Yellow
C— None
Greenish yellow
F— Conchoidal Brittle
Alteration product of lead min- erals. With galena, cerussite, mimetite, barite, limonite.
C — Rbombohedral F — Conchoidal, uiiev Brittle
In limestone, with quartz, and other copper minerals.
C— Dodecahedral, 2.4 Always blue and contains dia-
distinct seminated pyrite. Occurs as
F — Uneven ' contact mineral in crystalline
Brittle limestone.
Grayish green Grayish brown
Yellowish
—Prismatic, perfect, often conspicuous
Simple, pseudobexagonal crystals, and cleavage— 124° — important. In nearly all types of igneous rocks. With quartz, feldspar, pyroxene, chlorite, calcite.
jyGoogle
B. Miherals With Hob-Metallic Ldster
Streak — Blue, green, brown, yeUoi
Crystallization
Structure
CrystabC
Luster Transparency
ADOtTE (Pyroxene) Monoclinic
C — Short, prismatic, Silicate of Ca, Mg, Fe, Al, et. thick columnar;
prism angle 87° Moaea M — Compact, granular, KmuB, Dana, Paraona disseminated
Vitreous Sub metallic Translucent to opaque
Blackish
green Leek green
Turquois
Amorphous 7
Waxy
Sky blue
M— Reniform, stalaotitic,
Dull
Bluish green
Ai/Oh),Po<.H,0
disseminated, round-
Opaque to
Apple green
181. 512.
352 ed pebbles
Glaucophanb
(Amphibole)
Monoclinic
Vitreous
Azure blue
C— Prismatic, indistinct
Pearly
Lavender blue
Silicate of Ca, Mg
Fe, Al
Na,
H — Columnar, fibrous
Translucent
Grayish blue
etc.
granular
2S5,
3W)
Chloritoid
Monoclinic
C— Tabular, six-sided
Vitreous Pearly
Dark green Grayish green
H,FeAI,SiO
M— Folia ted, scaly, platy; tan- and sheaf-like aggregates
opaque
Blackish green
222,
Streak— Uncolored, iriiite, or Egt gray'
Cerargyrite (Horn silver)
Adamantine Grayish
101. 319,
C— Rare Waxy green
M — -Wax-like crusts and Greasy Greenish
coatings; Btalactitic, Transparent to Grayish blue
dendritic translucent
Glauconite
Dull
Dark green
M— Sand, earthy, dis-
Opaque
Light green
FeKSi,0,.H,0?
1.
PyrophylUte
Orthorhombic
Greasy
Apple green
C— Indistinct
Pearly
Grayish green
H,Ali.O.,
M— Radiated fibrous,
Dull
Brownish
lamellar aggregates;
Translucent to
green
231,
482,
423 granular, compact
opaque
ijGoogle
3. 6REEIT, BLUE, OR BLUE VIOLET m COLOR Hardness over 3
Cleavage Fracture -F Tenacity
Characteristics and
6. Pale green 6. Grayish green
6. Fate green
6. Grayish blue
C— Prismatic, perfect, conspicuous — 87° Brittle
Crystals, usually eight-sided, more rarely four sided; pseudotetrago- nal with prism angles of 87° and 93°. Cleavage less distioct than on hornblende. Common in basic eruptive rocks and crystal- line limestones.
Secondary mineral, , common in thin veins, crusts, or coatings. With limonite, quartz, feldspar.
In metamorphic rocks. With mica, amphibole, pyroxenes, gar- net, epidote, aoisite.
6. Pale green
C — Basal, perfect,
conspicuous F— Scaly Brittle
Sometimes softer due to alteration. Recognized by micaceous struc- ture, perfect cleavage, and hardness. In clay slates, mica schists. With corundum, garnet, chlorite, hornblende.
1. White, shiny 1.6 Gray, shiny
C— None
F — Conchoidal
Highly sec tile
1. Greenish white F — Earthy
C— Longitudinal F — Fibrous, unevi Laminffi flexible
Cuts like wax, yielding shiny sur- faces; on exposure turns violet, brown, or black. With silver minerals — argentite, native sil- ver; also limonite, calcite, barite.
Commonly as green sand. Resem- bles earthy chlorite. Dissemi- nated in sandstones, limestones, and marls.
Soft and greasy like talc, but usually in radiating fibers. In schistose rocks. With cyanite, lazulite, topaz, g|raphite.
ijGoogle
B. Huterals With Hov-Hetallic Luster
Streak— Uncolored. wHt, or light gray
Name, Compoeitioi
,and
Structure
CryrtalH-C
Hasaive-M
Luster Transparency
Color
Asbestos, variety H.Mgi,0.
Orthorhombie 7 M— Fibrous, coarse or flue; felted
Silky
Silky metalUo
Opaque
Light green Olive green
Kmua, Dans, Piinoiia
Ampkiboh Silicate of Ca, Mg, Fe, Al
etc.
Monoelinic ? H— Fibrous, coarse or fine; felted
Silky Opaque
Greenish
♦KAOLmiTE (Kaolin)
230. 481.
C — Scaly, hexagonal or
Une, rare M— Compact, friable, clay-like
Dull Pearly Opaque to translucent
Bluish Greenish
Vivianite
Fe,CP0.),.8H,0
178. 808,
C— Prismatic, tabular H— Reniform, globular, with radial fibrous structure; earthy
Vitreous DuU
Translucent to opaque
Indigo blue Bluish green Blackish green
TALC, varieties
Foliated
H,Mgi.O„
227, 479. 421
Monoelinic
C— Thin tabular, indis- tinct M— Foliated, globular,
granular, compact, fibrous
Pearly Greasy
Opaque to transparent
Pale green Apple green Dark green
CHLORITE (FyrDchlorite, clino- chlorite)
223. 472. *ia
C— Tabular, six-sided, often bent, twisted
M— Foliated, scaly, gran- ular, earthy
Pearly
Vitreous Dull
Translucent to opaque
Grass green BrownUh
green Blackish
green
Ni,(A80J,,8H,0
Monoelinic
C— Hair-like, indistinct,
M— Earthy, crusts, tains
DuU Vitreous Opaque to trislucent
Apple green Light green
ijGoogle
3. GREEH, BLUE, OR BLUE VIOLET DT a>LOR
Hardness 1 to 3
Hard-
Streak
Cleavage -C Fracture -F
Tenacity
Specific Gravity
Characteristics and
Associates
White
F— Fibrous Flexible
Delicate, fine, parallel, flexible fibers, easily separable, called short fibered asbealoa; compare below. In veins or seams in compact serpentine.
White
F— Fibrous Flexible
1,
Long fibered asbestos, parallel, flexible fibers. Compare above.
White Bluieh, white
C— Basal (scales) F— Earthy Brittle
Clay odor when breathed upon. Usually adheres to tongue and becomes plastic when moistened. Greasy feel. With quartz, feld- spar, corundum, diaspore, topaz.
Bluish white Greenish white White
C — Cli nopinacoidal F— Fibrous, earthy Sectile, thin laminte flexilje
Usually massive. Color and streak dariien on exposure. In clay, peat, bones, shells. With limonite, pyrrhotite, pyrite.
White
Basal, conspicu- ous on fohated
F — Uneven Sectile, lamitiEe flex- ible
2,6
Greasy or soapy feel. Foliaied, easily separable, inelastic folia or
tUe, coarse to fine granular, more or less impure, H 1.5-2.5. With serpentine, dolomite, mag- nesite, actinolite.
White Greenish white
C— Basal, conspicu- ous, when foliated F— Scaly, earthy Tough to brittle
Lamins flexible but inelastic, with slightly soapy feel. Com-
With magnetite, magnesite, gar- net, diopside. Often as scaly or dusty coating on other minerals. Pseudomorphous after garnet.
White Greenish white
C— None
F— Earthy
3,
Common alteration product ot nickel-arsenic minerals. With niccolite, ohloanthite, calcite.
ijGoogle
milERALS WITH HOH-HETALLIC LUSTER
Streak — Uncolored, white, or light gray
Name, Composition, and
Crystallizatoi Structure CryetalB-C Massive— M
Traneparency
Helanterite (Copperas)
Dsaa. Poreons
Monoclinic C— Rare
M— Capillary, fibrous, Moe8~ stala otitic, concre- tionary, powder
Vitreous Green
Dull Yellowish
Transparent to green translucent
Cubic Vitreous
C — Cubes, alone or with Transparent to
octahedron translucent H — Granular, compact
*HALITE (Rock aalt)
NaCl
Cubic
C— Cubes, often skeletal or hopper-shaped
M — Compact, cleavable, granular, fibrous, Btalactitic, crusts
Vitreous Transparent to opaque
Bluish
Blue Greenish
Bnicite Mg(OH).
90. 351,
Hexagonal C— Broad tabular M— Foliated, fibrous, scaly
Pearly
Vitreous Transparent to translucent
Greenish white Green Bluish
Chrysocolla H,CuSiO..H,0
Amorphous 7 M— Compact, reniform, incrustations, seams,
Greasy
Dull
opaque
Green
Greenish
blue Blue
Garnierite
H,{Ni,Mg)8iO,
229. 47ft.
Amorphous 7 M— Compact, reniform, earthy
Dull
Greasy
Opaque
Pale green Apple green Emerald
green
Actinolite (Amphibole) Cft(ME,Fe).(SiO0.
Monoclinic Vitreous Grass green
C — Fine, acicular Silky Grayish
ttInterwoven fibrous Translucent to green
aggregates opaque
:y
3. Green, Blx7E, Or Blue Violet Iv Color
HardneBs 1 to 3
Cleavage -C Fracture — F Tenacity
Specific
White
C— Basal, not con-
F— Conchoidal,
earthy Brittle
White
C— Cubic
F— Conchoidal Brittle
2.B
White
C— Cubic, perfect, c
spicuous F— Conchoidal Brittle
White
C— Basal, perfect,
conspicuous Thin plates or sea flexible
White
QreeniEh white Bluish white
F— Conchoidal Brittle
C— None h
F— Conchoidal, earty Brittle
On exposure loses water and crumbles to powder. Sweet, astringent taste, somewhat me- tallic. Oxidation product of iron sulphide minerals — marcfisit e, pyrite, chalcopyrite, pyrrhotite.
Color due to impurities. Salty, bitter taste. May absorb mois- ture and become damp. Usually in salt deposits. With halite, kainite, carnallite.
Characteristic cubical cleavage and saline taste. May absorb mois- ture and become damp. With shale, gypsum, anhydrite, poly-
Distinguinhed from mica by non- elasticity and distinct pearly luster. Foliated talc is softer with greasy feel. With serpen- tine, limestone.
Usually recognized by enamel-like appearance, conchoidal fracture, and non-fibrous structure. When impure brownish or black- ish. With copper minerals — - malachite, azurite, chalcopyrite; also limonite.
Often as rounded, pea-shaped masses, with varnish-like sur- faces and earthy interior. May adhere to tongue. With olivine, serpentine, chromite, talc.
Masses of delicate, interwoven fibers — aelinoHte sekist. A pale grayish green, highly ferruginous variety (griiiiente, Fe.(Si05),) associated with quartz and mag- netiteis teTmedmagnetiie-granerite schist.
.jGoogle
B. UnERALS WITH ROIT-HETALLIC LtlSTER
' Strak
-tlncolored, white, or Ugl
Crys;:ilii2Htion
t gray
Nam;, Comriosition, and
fitnicture
Luster
Color
lU'Eorencea
Crystals -C
Transparency
Massive -M
Chalcanthite (Blue vitriol)
Triclinic
Vitreous
Deep blue
C— Tabular, Bmall, rare
Dull
Sky blue
CuS0..5H,0
H — Crusta, reniform, atalactitic, fibrous,
Translucent
Greenish blue
151. S34. 288
powdery
LeadhiHitt
Peariy
Greenish
Adamantine
PbSO. 2PbC0,.PbC0H),
agonal; twins.
Transparent to
trillings
translucent
la. 629.
M— Compact, lamellar
Gibbsite (Hydrargillite)
Vitreous
Greenish
C— Pseudohexagonal,
Pearly
Bluish
Al(OH),
tabular, rare M— Stalactitic, mam mil- iary, surface smooth, internal structure fibrous; scaly aggre-
Translucent
white
82, 351. 360
gate
*PHLOOOPirE
Monoclinio
Pearly
Green
C— Prismatic, tabular.
|(K,H).Mg.Al(SiO.),
hexagonal or ortho-
Transparent to
rhombic outline,
translucent
often large or coarse
5 217. 468. 419
Ibiotite
scales
Pearly
Brownish
C— Tabular, hexagonal
Submetallio
green
(K,H),(Ms,Fe),(AI,Fe),-
or rhombohedral
Transparent to
Blackish
(SiO.).
habit M— Plates, disseminated
opaque
green
: 216, 487, 418
scales
BARITE (Heavy spar)
Orthorhombic
vitreo
Bluish
C— Tabular, prismatic.
Pearly
Greenish
BaSO,
crested divergent
Transparent to
groups, common
opaque
M— Compact, lamellar,
fibrous, oleavable.
135, 524, 318
reniform
ijGoogle
3. GREGH, BLUE, OR BLUE VIOLET DT COLOR Hudneis 1 to 3
Cleavage — C Fracture -F Tenacity
Specific
. Gravity I
C — Indistinct
F — Conchoidal, earthy
Brittle
C — Basal, perfect F — Conchoidal
Rather sectile
DiEagreeable metallic taste. Oxidation product of copper sul- phide miaerals. With chal- oopyrite, bomite, melanterite,
pyrite, goslarite.
Soft and very heavy. Twins and triUings resemble those of aratco- nite. Usually with lead min- erals, but sparingly. Peeudo- morphouB after calcite, galena.
C — Basal, not conspic-
Strong clay odor when breathed upon. With bauxite, natrolite, limonite, corundum.
2.6 White 3. Gray
C- — Basal, perfect, con
spicuous Tough, lamins very
elastic
Especially characteristic of crys- talline limestones, dolomites, schist. With pyroxenes, amphi- boles, serpentine, apatite.
2.6 White 3. Grayish
—Basal, peri'ect, con- spicuous
3ugh, laminie of fresh biotite very elastic
Easily recognized by i highly perfect cleavage, and elas- ticity. Important constituent of many igneous and metamorphic rocks — granite, syenite, gneiss.
C— Basal, prismatic,
conspicuous F — Uneven Brittle
Characterized by rather high specific gravity and cleavages. In metalliferous veins; pockets, lenticular masses in hmestone. With galena, sphalerite, chlorite, chalcopyrite; manganese and iron minerals.
jyGoogle
B. Urerals With Honcetaluc Luster
Streak
— Uncolored, white, or gray
Name, Compositioa, s References
nd
Crystallieation Structure Crystals Massive -M
Luster Transparency
Color
AUopbane AliO,,6H,0
"St
Paraoni
Amorphous
M— Reniform, mammil-
lary, stalactitic, in-
cniating
Vitreous Greasy
Sky blue Bluish green Deep green
CALCITE CaCO,
111. 354,
Hexagonal
M — Cleavable, granular, fibrous, compact
Vitreous
Dull
Transparent
to nearly opaque
Sky blue Deep blue Greenish
WuKenite PbMoO.
139, Ml,
Tetragonal
C— Square, thin tabular; more rarely pyrami- dal
M— Coarse, fine grained
Greasy
Transparent to translucent
Light green Olive green
Streak
— Uncolored, white, or light gray
*Gibbsite (Hydrargillite) Al(OH),
82. 361,
MoQoclinic
C— Pseudohexagonal, tabular, rare
M — Stalactitic, maramil- lary, surface smooth, internal structure fibrous; scaly aggre- gates
Vitreous Pearly
Greenish Bluish white
Ahhydrite
CaSO.
133, 528,
Orthorhombic
C— Thick tabular, pris- matic, rare
M— Granular, compact, fibrous, lamellar, cleavable, reniform
Vitreous Pearly
Translucent to opaque
Bluish Grayish blue
Blue
CELESrnE
SrSO.
134. S28.
Orthorhombic
C— Tabular, prismatic,
common; pyramidal M— Compact, cleavable,
fibrous, granular,
reniform
Vitreous Pearly
Transparent to
Sky blue
Blue
Greenish
ijGoogle
3. greeh. blue, or blue violet m color
HardnesB 1 to 3
Cleavage - Fracture — Tenacity
Specific Gravity
F — Conchoidal, earthy 1 9 Structure resemblea opal. In fie- Brittle surea and cavities with copper
and iron minerals.
C — Rhombohedral per- fect, conspicuous F — Conchoidal Brittle
Rhombohedral cleavage generally characteristic. Geavagea often
show Btriations.
C — Pyramidal, india-
P — Conchoidal, uneven - Brittle
Square plates, sometimes with forms of the third order. With lead minerals—galena, pyromoi phite, vanadinite.
Hardness 3 to 6
C — Basal, not conspic- Tough
Strong clay odor when breathed upon. With bauxite, natrolite, limonite, corundum.
C — Pinacoidal, perfect, 3 directions at 90° F — Conchoidal Brittle
Pseudocubical cleavage, sometimes noted. Granular varietiei resem- ble marble. Not as heavy as celestite or barite. In limestone, shale. With halite, gypsum.
C — Basal, prismatic,
conspicuous F — Uneven Brittle
Heavier than calcite, anhydrite; lighter than barite. In hme- stones, dolomites, shales. With sulphur, gypsum, aragonite, ha- lite, galena, sphalerite.
:y
B. miTERALS WITH VOU-ICETALLIC LUSTER
Streak
Name, CompoBition, and
CrjTBtaUization Structure Crystals -C Massive -M
Luster Transparency
Color
BAKITE (Heavy spar) BaSO.
KraiH, Dmm 13S. 624.
- Orthorhombic C — Tabular, prismatic, crested divergent groups, common Moms M— Compact, lamellar, pL fibrous, cleavable, 3JS reniform
Vitreous Pearly
translucent
Bluish Greenish
'AMGLESITE PbSO.
Orthorhombic
C— Prismatic, tabular,
pyramidal H~Compact, granular,
nodular
Adamantine Greasy
Transparent to translucent
Blue
Chrysocolla HAiSiO..H,0
Amorphous T
H— Compact, reniform,
incrustations, seams.
Vitreous
Greasy Dull
Blue Bluish
green
stains, earthy Translucent to Green
opaque
SERPEHTiHE H,Mgi,0,
Orthorhombic 7 Greasy Light green
CUnknowQ Waxy Olive green
H — Compact, columnar. Translucent to Yellowiah]
fibrous, lamellar, opaque . green
granular Blackish green
(A1,0H),(P0.),.6H,0
Orthorhombic
Vitreous
Green
C — Capillary, small
Bluish
H— Cruste, globular or
Blue
radial fibrous struc-
ture
ijGoogle
3. Greek, Blue, Or Blde Violet In Color
Cleavage - Fracture — Tenacity
Specific Gravity
C — Basal, priHmatic,
conapicuoUB F— Uneven Brittle
Characterized by rather high spe- cific gravity and cleavages.
metalliferous lenticular i With galei
pockets, tea in limestone. sphalerite, cbal-
C — Basal, prismatic F — Conchoidal BritUe
Luster and very high specific gravity important. Oxidation product of lead minerals. Usu- ally in cracks and cavities. With galen
White
Greenish white Bluish white .
F — Conchoidal, splin Brittle
Usually recognized by enamel-like appearance, conchoidal fracture, and non-fibrous structure. When impure brownish or black- ish. With copper minerals- malachite, azurite, chalcopyrite; also limonite.
Smooth and greasy feel. Often spotted, clouded, and multi- colored. Sometimes crossed by seams of asbestos (chrysotile). Verd'antique, massive, green and mixed with calcite, dolomite, or magnesite; takes an excellent polish. With magnesite, chro- mite, gamierite, pyrope, plati-
C — Pinacoidal, domatic F— Conchoidal, uneven,
fibrous Brittle
Secondary mineral occurring on surfaces of rocks or minerals, as crystalline crusts with pro- nounced radial, fibrous structure.
DigitzcdCy.GoOgIC
B. Wherals With Roh-Hetallic Luster
Streak— Uncolored, bite, oi tight gnj
Cryatallizatioi Btmcture Crystals -C Massive— M
ARAGOHITE CaCO,
Kraiu, Dana,
lie. 361, Scorodlte FeAs0..2H,0
179, 509.
Orthorhombic
C— Cliisel- or spear- shaped; pseudohex- agooal prisms; radial columnar, acicular
Vitreous Transparent to translucent
Greenish Bluish
Violet
MOM8 aggregates ptL M— Stalactitic, renitorm, 332 cruata, oolitic
Orthorhombic Vitreous Pale green
C— Priamatic, pyramidal Greasy Bluish green
drusy Translucent Blackish
H — Botryoidai, fibrous, green
earthy, crusts Blue
STROHTIAHITE SrCO,
Orthorhombic
C — Spear-shaped, colum- nar, acicular, often in diveient groups
H — Granular, compact, botryoidai, fibrous
Vitreous Light green
Transparent to Apple green
translucent
Pyrohorphite
PbsCKPOi),
Hexagonal
C — Prismatic, thick tabu- lar, rounded and barrei-shaped; acicular
M — Globular, reniform, disseminated, crusts
Greasy Dark green
Adamantine Emerald green
Translucent to Yellowish
opaque green
*RHODOCHROSnX MnCO,
Hexagonal Vitreous
C — Rhombohedral, rare Translucent H — leavable, granular,
compact, botryoidai,
cruBta
FLVORITE (Flu(
Cap,
C-Cubes, alone or modi- fied, well developed, common; penetra- tion twins
K — Cleavable, granular, fibrous
Vitreous Greenish
Transparent to Bluish green
nearly Blue violet
opaque
:y
3. Greev, Blue, Or Blue Violet Iif Color
Cleavage — C Fracture '"F Tenacity
C— Pinacoidal, pris-
Twins common, often paeudohex- agonal— prism and striated base. In cracks knd cavities with ore deposits; deposition from hot Bprings; in ahells. With gypsum, celestite, sulphur, Biderit, zeo-
White Grayieh Greenish white
C— Imperfect
F— Uneven, conohoidai
Brittle
White
C— Priamatic, indis- tinct F— Uneven Brittle
White
Yellowish white
C— None Brittle
With arsenopyrite, enargite, limon-
ite, pyrite.
Similar to aragonite. Divergent columnar structure, and higher specific gravity characteristic. In ore deposits; independent beds. With galena, barite, calcite.
Common alteration product of lead minerals. With galena, cemssite, mimetite, barite, limonite.
C — Rhombohedral,per-
fect, conspicuous F— Uneven Brittle
C — Octahedral, perfect,
conspicuous Brittle
May turn brown or black on ex- posure, due to MnO,. With ore deposits. With galena, sphaler- ite, pyrite, alabandite, psiiome- lane, silver minerals.
May show fluorescence. Easily recognized by crystal form, octa- hedral cleavage, and hardness. Common gangue of metallic ores — galena, sphalerite, cassiterite; also with calcite, barite.
:y
B. Miderals With Itoh-Hetallic Luster
Streak
— Dncolored, white, or light gray
Crystallization
Name, Compoaition, and
Structure
Luster
Color
Referencea
Crystals
Transparency
Massive '-M
CYAKITE (Disthene
kyanite)
Triolinic
Vitreous
Sky blue
C— Long, bladed, with-
Translucent to
Greenish blue
AliSiO,
out good termina- tions; sometimes curved and radially grouped
transparent
Bluish white
Kraus,
Dana
Parson
M— Coarsely bladed, co-
189, '
434,
3B2
lumnar, fibrous
ScheeUte
Tetragonal
C— Pyramidal, smalt.
Adamantine Greasy
Greenish
CaWO,
more rarely tabular
M— Drusy cruBts, reni-
form, granular, dis-
Transparent to translucent
139,
540,
Apatite
Hexagoual
Greasy
Grass green
C— Prismatic, thick, tab-
Vitreous
Brownish
Ca,F(PO.),
ular, common, some-
Translucent to
green
times large with
opaque
Bluish green
rounded edges
Blue violet
MCompact, fibrous,
nodular, reniforra
♦HEJOMORPHITE (Cakmrne)
Orthorhombic
Vitreous
Pale blue
C — Thin tabular, pyram-
Bluish green
idal, hemimorphic, highly modified M— €ompact, globular, stalactitic, fibrous.
opaque
Pale green
186,
446,
granular
Smithsomite
Hexagonal
Vitreous
Green
C— Small, usually as
Dull
Grayish green
ZnCO,
druses or crusts H— Botryoidal, stalactit- ic, granular, fibrous.
Translucent
Greenish blue Blue
117,
340,
compact
Lazurite (Ipis lazuli)
Cubic
Vitreous
Azure blue
Translucent to
Violet blue
(Na„Ca),AUAl(Na80,
NaS„-
H — Compact, irregular
opaque
Greenish blue
Cl)](SiO.).
grains
234,
ijGoogle
3. Oreeit, Blue, Or Blue Violbt Ik Color
Hudaesa 3 to 6
Cleavage -C Fracture -F Tenacity
C— PinacoidaJ, perfect, 3 5
C — Pyra.midal F— <onchoidal, ii Brittle
C — Basal, imperfect F — Conchoidal, unevei Brittle
Color irregularly distributed, fre- quently with lighter longitudinal margins. Hardness varies with direction, 4-5 parallel to long direction, 6-7 at right angles thereto. In gneiss, mica schist. With Btaurolite, garnet, corun-
Small, well developed octahedral' like crystals, usually on quartz; when massive high specific gravity important. With cas- siterite, wolframite, fluorite, apatite, molybdenite, topaz.
Crystals may be vertically striated and have fused appearance. Color often unevenly distributed — brownish spots. In crystalline limestones; metalliferous ore de- posits; igneous rocks. With quartz, cassiterite, fluorite, wol- framite.
White
C — Prismatic
Crystals often in sheaf-Kke groups
F — Uneven, conchoid- al Brittle
3,5
or druses in cavities. In lime- stone. With sphalerite, galena,
White
With zinc minerals, especially
Gray
not often observed F— Uneven, splintery Brittle
sphalerite, hemimorphite.
White
C— Dodecahedral, im-
Always blue and contains dis-
Bluish white
perfect FUneven
contact mineral in crystalline
Brittle
limestone.
ijGoogle
B. UniERALS WITH ITOn-HETALLIC LUSTER
Streak
— Uncokired, white, or light gray
Name, Composition, and
Structure
Luster
Color
References
Crystals -C Massive -M
Transparency
Datolile
Moaoclinic
Vitreous
Pale green
CPrismatic, pyramidal.
Greasy
Olive green
Ca(B.OH)SiO,
tabular, highly mod- ified M— Compact, fibrous, granular, botryoidal
Dull
Transparent to opaque
Kraua, Dana,
ParaoDi
192. 43S,
Monoclinic
Vitreous
Lazulite
Aaure blue
C— Acute pyramidal, tab-
Translucent to
Sky blue
Mg(AI.OH)s(PO.),
ular M— Compact, granular
opaque
178, 506,
TITAHITE (Sphene)
Monoclinic
Vitreous
Green
C— Wedge- or envelope-
Greasy
YeUowish
CaTiSiO,
shaped when dia-
prismatic when attached
Transparent to translucent
green
271. Ms.
M— Compact, lamellar
vitreous"
Sodalile
Cubic""" '
lavender blue
C— Dodecahedrons
Greasy
Sky blue
Na.AI,(AtCI)(SiO.), .
M— Compact, dissemi-
Transparent to
Dark blue
233. 412,
nated grains, nodular
translucent
Greenish
Cancrinite
Hexagonal
Vitreous
Green
C— Prismatic, rare
Pearly
Grayish blue
H,(Na„Cii).(NaCO,),Al
H— Compact, lamellar,
Greasy
Blue
3i.0„
columnar, dissemi-
Transparent to
233. 411.
nated
translucent
BEPHELITE (Nepheline,
Hejcagonal
Greasy
Grayish green
elffiolite)
C— Short prismatic, tab-
Vitreous
Brownish
(Na,K),Al,Si,0„
ular
Transparent to
green
H-Compact, dissemi-
opaque
Grayish blue
2:w, 40B,
nated grains
SCAPOLITE (Wernerite)"
Tetragonal
Vitreous
Grayish green
C— Thick prismatic,
Greasy
Bluish
/ nXa.Ali.O„C!
coaree, often large
n.Ca.Al,Si,0„
M— Compact, granular, fibrous, columnar
opaque
270, 42S,
ijGoogle
3. GREEH, BLDE, OR BLUE VIOUIT IH COLOR Hordiwfls 3 to 6
Cleavage Fracture — F Tenacity
6. White
5. White
B. Whit* 5.6 Grayish
C — Indistiftct F— Uneven Brittle
—Prismatic, conspic- uoua parting often
Crystals glaaay and usually well developed. Compact masses often with brownish, yellowish, reddish streaks' and spots. In cracks and cavities in basic igne- ous rocks. With calcite, prehn- ite, native copper, magnetite, zeolites.
Pyramidal crystals are pseudo- tetragonal and well developed. Disseminated in quartz, clay at slate. With corundum, cyanite,
with feldspars, pyroxenes, amphi- bolee, chlortt, scapolite, zircon.
C— Dodecahedral
F — Conchoidal, uneven
Brittle
C — Prismatic, perfect F — Uneven Brittle
Commonly massive and blue in
color Recognized by associates
nepheLte cancnnite, leucite,
feldspar zircon not with quartz.
Associates important — nephehte, sodalite, biotite, feldspar, titanite.
C — Prismatic
F — Conchoidal Brittle
Greasy luster and associates im- portant. With feldspar, can- crinite, biotite, sodalite, zircon, leucite; not with quartz.
Crystals may appear as though fused. Typical contact mineral. In metamorphic rocks, especially granular limestones. With pyroxenes, garnet, mica, amphi- boles, wollastonite.
ijGoogle
B. Minerals With Hoh-Hetallic Luster
StreokDncotOFed, white, or light graj
CryBtallization Structure Crystals -C Massive — M
Luster Transparency
Actinolite
Vitreous
Light green
C— Bladed, without ter-
SUky
Grayish green
Ca(Mg,Fe),(8iO.).
minations
Transparent to
Dark green
Moses
H — Columnar, fibrous,
opaque
KmuE, Dana
Tl
often divergent;
352. 400,
granular, compact
lORlfBLEllDE
Vitreous
Blackish
C — Long prismatic.
Silky
green
Silicate of Ca, Mg,
253. 387.
Fe, Al, etc.
prism angle 124°; often with rhombo- hedral-like termi- nations H— Bladed, fibrous, granular, compact
opaque
Dark green
Enstatite
Orthorhombic
Vitreous
Grayish green
C— Prismatic, rare
Pearly
Brownish
M— Fibrous, lamellar.
Translucent to
green
241, 384,
columnar, compact
opaque
Olive green
Brohzite
Orthorhombic
Broniy
Grayish green
C— Prismatic, rare
saky
Brownish
(Mg,Fe).(8iOJ,
HFibrous, lamellar,
TranBlucent to
green
opaque
Olive green
242. 385,
Hypersthene
Orthorhombic
Pearly
Brownish
242. 3S£. 3S4
1 DIOPSIDE I CaMg(SiO,
—Prismatic, tabular. Metalloid al green
rare Translucent to Blackish green
Granular, foliated, opaque cleavable aggregates
Monoclinic Vitreous Pale green
C — Prismatic, thick co- Dull Bright greeh
lumnar, prism Transparent to Dark green
angle 87° opaque H — Compact, granular,
columnar, lamellar
' 243. 388. 386
I augite"
I Silicate or Ca, Mg, Fe, Al,
Monoclinic Vitreous
C — Short prismatic, thick Submetallio
columnar, prism Translucent to angle 87° opaque
M — Compact, granular, disseminated
Blackish green Leek green
:yGoogle
3. GREEK. BLUE, OR BLUE VIOLET m COLOR Hardness 3 to 6
Cleavage Fracture — F Tenacity
CPriBmatic, often conspicuous, 124° Brittle
2.9 In talc and chlorite echists. With 3.2 serpentine, epidote, calcite.
Nephrite and jade are compact J varieties.
Gray C — Prismatic, often
Greenish gray conspicuous, 124°
Brownish gray Brittle
2.9 Simple, pseudohexagonal crystals, 3,3 and cleavage — 124° — important.
Common in many types of rocks.
With quartz, feldspar, pyroxene,
chlorite, calcite.
White
C— Prismatic, pinacoid-
Often softer due to alteration to
Greenish white
al
serpentine. Commonly in basic
Grayish
F — Uneven Brittle
igneous rocks. With olivine, serpentine, chondrodite, talc.
White
C— Prismatic, pinacoid-
Cleavage surfaces often fibrous or
Grayish
al, often conspic-
F — Uneven
Brittle
lamellar, irregular or wavy, with distinct broniy luster. Darker than enstatite. In basic igneous rocks.
G.
White
C— Brachypinacoidal ,
Copper red iridescence often noted.
Gray
conspicuous
Brownish
gray
F— Uneven Brittle
In basic igneous rocks. With feldspar (labradorite), olivine, hornblende, pyrrhotite, magne- tite.
White
C— Prismatic; conspic-
Crystals prismatic and pseudo-
Gray
uous basal parting F— Uneven Brittle
tetragonal with distinct basal parting. May have colorless and darlt green zones. In crystalline Umestones and schists. With vesuvianite, garnet, scapolite, spinel, apatite.
White
C— Prismatic, perfect.
Crystals usually eight-sided, more
e.
Gray
conspicuous-87'
rarely tour-sided; pseudotetrago-
Greenish
gray
Brittle
nal with prism angles of 87° and 93°. Cleavage less distinct than on hornblende. In basic igneous
ijGoogle .
B. HinERALS WITH HON-HETALLIC LUSTER
Streak — Uncolored, white, or light gray
Crystallization
Structure Luster
Crystals — C Transparency
Massive
Chlobastroutb
C— Unknown
Vitreous
Green
M — -Rounded grains,
Silky
Bluish green
H,CaU(SiO.). ?
Hoees
pebbles
Translucent
Dark green
Kraus, Dana,
Paraons
213,
WillNnite
Hexagonal
Vitreous
Apple green
C— Prismatic
Greasy
Yellowish
M— Compact, granular,
Translucent to
green
208. 422,
disseminated grains
opaque
Opal
Amorphous
Vitreous
Green
KRenitorm, botry-
Greasy
Bluish green
SiO,.icH,0
oidal, compact
Translucent to
Blue
89, 32S,
opaque
Turquois
Amorphous 7
Waxy
Sky blue
M— Reniform, stalactitic,
Dull
Bluiah
Au(Oh),Po,.H,0
Opaque to
green
181. 512.
rounded pebbles
Apple green
♦Amblygonite
Triclinic
Pearly
Greenish
C— Rare
Vitreous
Bluish
Li{A!F)PO,
M — Cleavable, columnar, compact
Translucent
173. 503,
Streak — Dncolored, white, or light gray
I mCROCLIHE, variety Triclinic Vitreous Bright green
I Amazonelone C — Prismatic, thick tabu- Pearly Bluish green
I KAlSljOj lar, twins Translucent to
I [ H — Cleavable, granular, transparent
compact, dissemi- ; 204. 373, 380 nated
Labradorite Triclinic
Vitreous
Grayish green
C— Thin tabular, often
Pearly
Greenish
Silicate of Ca,Na,Al with rhombic cross-
Translucent
to nearly
M— Compact, cleavable.
opaque
268, 379. 383 granular
ijGoogle
3. Green, Blue, Or Blue Violet Is Color
Hardness 3 to 6
Cleavage -C Fracture -F Tenacity
Rounded grains in basic, amygda- loidal rocks, also as pebbles. Color unevenly distributed. May show radial, fibrous struc- ture and chatoyancy.
C— Basal F — Uneven Brittle
Characterized by associates — franklinit {black), aincite (red), rhodonite (flesh red), calcite.
F — Concboidal, BpicuouB
Structure and fracture character- istic. Precious opal, play of colors. Id veins, cavities, and masses of irregular outline.
C— Basal, perfect, con- spicuous; macro- pinacoidal, domatic
F — Uneven, conchoidal
Brittle
Secondary mineral, commonly in thin veins, crusts, or coatings. With quartz, feldspar, kaohn, limonite.
Usually in cleavable masses with perfect cleavage in one direction. With lepidolite, rubellite, topaz, wavellite, petalite.
HardneBS over 6
Basal, brachypina- coidal, conspicuous, 90° SC
F— Uneven
Brittle
Slightly inclined cleavages; may show twinning striations on basal pinaooid. With quartz, other feldspars, mica, hornblende, topaz, phenacit.
C — Basal, brachypin- aooidal, conspic-
FUneven, concboid- al Brittle
Often with play of color — yellow, green blue, red. Inclined cleav- ages are striated. In basic igneous rocks. With pyroxenes, amphiboles.
ijGoogle
HDIERALS WITH ROIf-HETALLIC LUSTER Streak— Uncolored, white, or Ht gray
CrystaUiKatioQ Structure Crystals -C Haaidve— M
Luster Transparency
Silicate of Mg, Pe, Ca, Al, Na
Monolinic
C — Prismatic, iadietinct H — Columnar, fibrous, granular
Vitreous Aeure blue
Pearly Lavender blue
Translucent Grayish blue
Ca,AI,(AI.OH)(SiO.),
Orthorhombic Vitreous Grayish green
C — Prismatic, deeply Pearly Apple green
striated, bent, with- Translucent to ! out good terminations opaque „ H — Columnar, broad bladed, fibrous
Prehnite
H;a,Al,{SiO.),
Orthorhombic Vitreous Light green
C — Tabular, prismatic; Waxy Apple green
curved, sheaf-like Transparent to Yellowish
groups translucent green
M — Botryoidal, stalactit-
ic, radial fibrous
213, 44Z,
*Spodumene (Pyroxene), variety HiddeniU LiAI(SiO.),
Uonoclinic
C — Long prismatic, f often etched
Vitreous Yellowish
Transparent to green
translucent Emerald green
*SiIlinunite (Fibrolite)
Orthorhombic Vitreous Grayish green
C — Long, thin needle- Silky Pale olive
like Transparent to green
M — Fibrous, columnar, translucent
radiating
R/'R."'B,(SiOJ, R" -CaJ'e,Mn,Mg R"'=AI,Fe
Triclinic Vitreous Green
C— Broad tabular, with Transparent to Yellowish
sharp edg translucent green
M — Lamellar, granular Plum blue
:y
3. OREEH, BLUE, OR BLUE VIOLET Df COLOR
Cleavage Fracture Tenacity
CharacteriBtica and Aeaociates
6. Bluish gray
In metamorphic rocka. With mica, amphiboles, pyroxenes, garnet, epidote, zoisite.
White
C— Pinacoidal, perfect,
conspicuous F— Uneven Brittle
3,4
broken, columnar masses. In blende, cyanite, epidote, garnet.
veBuviaaite, feldspar.
C — Basal, indistinct
F.Uneven
Brittle
Massive varieties usually have rough, crystalline surfaces and internal, radial fibrous structure. Color fades on exposure. In veins and cavities in basic igne- ous rocks. With pectolite, dato- lite, epidote, native copper, zeo-
C — Pinacoidal F — Uneven Brittle
Small, transparent oryetak, resem- bling green diopside. In cavities in granitic rocks. With beryl,
monazite, rutile.
Crystals often bent, striated, edges rounded, without good terminations, and often inter- laced. In metamorphic rocks- gneiss, mica schist. With anda- tusite, zircon, garnet, iolite.
C — Pinacoidal 3.3 Crystals sharp wedge-shaped,
' F — Conchoidal glassy, and frequently coated and
Brittle intergrown with green chlorite.
With quartz, adularia, albite,
hornblende.
:y
B. HIHERALS WITH IfOIf-HETALLIC LUSTER Streak — Dncolored, white, or Ugbt gray
CryetallizatioD Structure CrystaU-C Massive —M
Transparency
Ca,(AI,Fe),(Al . OH) (SiO.) ,
Duia, Panofu
MoDoclinic Vitreous Blackish green
C — Prismatic, elongated Transparent to YeUowish
and deeply striated opaque green
parallel to b axis; Brownish
usually tenninated green
oa one end only Pea green H — Columnar, fibrous, parallel and diver- gent; granular
I'Diaspore AIO.OH
Orthorhombic Vitreous Greenish
C— Broad columnar, tab- Pearly Violet blue
ular, rare Transparent to
H — Scaly, confused translucent
fibrous or bladed aggregates
Ohloritoid HJ-eAliO,
Monoclinic Vitreous Dark green
C — Tabular, siz-sided Pearly Grayish green
M — Foliated, scaly, platy; Translucent to Blackish
fan- and sheaf-like opaque green
aggregates
CYAHITE (Disthene, kyanite)
Ardaldsite
Triclinic Vitreous Sky blue
C — Long bladed, without Translucent to Greenish blur good terminations; transparent Bluish white
sometimes curved and radially grouped M — Coarsely bladed, columnar, fibrous
Orthorhombic Vitreous Pale green
C — Prismatic, rough, Dull Olive green
nearly square, often Translucent to
large and without opaque
terminations H — Columnar, fibrous,
granular, dissemi-
:y
3. GREEK, BLUE, OR BLUE VIOLET UT COLOR Hardness over 6
Cleavage Fracture — F Tenacity
Speeifle Gravity
White Grayish
Crystale are often dark or blackish green, masisive aggregates lighter colored. With quart*, feldspar, garnet, hornblende, pyroxene, magnetite, native copper, zeo-
C — Pinacoidal, c
apicuoos F — Conchoidal Very brittle
With corundum, emry, dolomite, margarite, chlorite, magnetite.*
White C— Basal, perfect, c
Greenish white spicuous
Grayish F — Scaly
Brittle
C — Pinacoidal, perfect,
conspicuous Brittle
Sometimes softer, due to alteration. Easily recognized by micaceous structure, perfect cleavage, and hardness. In clay slates, mica schists. With chlorite, bom- blende, garnet, corundum.
Color irregularly distributed, fre- quently with lighter longitudinal margins. Hardness varies with direction, 4-6 parallel to long direction, 6-7 at right angles thereto. In gneiss, mica schist. With ataurolite, corundum.
C — Prismatic F — Uneven Brittle
Due to alteration, surfaces may be covered with scales of mica, hence, softer. In metamorphic rocks, often as rounded or knotty pro- jections. With cyanite, silli- manite, garnet, tourmaline.
jyGoOgIc
B. HinERALS WITB nOH-HETALUC LUSTER Streak — Uncotored, white, or light gray
Crystallizatioa
Name, Composition, and
Structure
Luster
Col r
References
CrystalB-C Massive -M
Transparency
Vesdyiahite
Tetragonal
Vitreous
Green
C — Short prismatic
Greasy
Brownish
CaJAl(OH)]A],{SiO.).
H — Compact, granular.
Translucent to
green
Mows
aggregates with par-
opaque
Bluish
Kraun. Dsas,
allel or divergent
striations
OLIVIHE (Chrysolite, peridot)
Orthorhombio
Vitreous
Grass green
C— Prismatic, thick tabu-
Transparent to
Olive green
lar
Yellowish
M— Romided, dissemi-
green
nated glassy grains;
204. 420, 398
GARRET, varieties
Cubic
Vitreous
Pale green
Gros$iilarUe
C— Dodecahedrons, te-
Transparent to
Grass green
R,"'R,"{SiOJ, Uvarovite
tragonal trisoctahe-
opaque
Emerald green
R"'-Al,Fe,Cr AndradUe
drone, alone or in
R"-Ca,Fe,Mg
combination M — Granular, compact, lamellar, dissemi- nated grains, sand
208. 415, 3M
Hexagonal
Vitreous
Green
varieties
C— Prismatic, horizon-
Greasy
Greenish blue
SiO, ChloriHc
tally striated
Transparent to
Blue
Cat's eye
H — Compact, granular
opaque
Blue violet
Amethyst
Cryptooryatalline
Hexagonal
Waxy
Light green
varieties
C — Never in crystals
Vitreous
Dark green
Chakedony
M— Nodular, spotted.
Translucent to
Grayish blue
Chrysoprase
concretionary, stal-
opaque
Greenish blue
Prase
actitic, compact
Plasma
HelMrope
70. 324, 372
Boracite
Psendocubic
Vitreous
Greenish
C— Tetrahedral, cubical.
Transparent to
Bluish
Mg,Cl.B..O„
M— Compact, nodular.
opaque
162, 61S. 358
fine fibrous
Uooommon ijolor.
Diai.zodBjGoogle
3. Oreeh. Blue. Or Blue Violet Ih Color
Cleavage Fracture - V Tenacity
Gravity
Characteriatics and Associates
C — Basal, prismatic,
indistiDct F— Uneven Brittle
In crystalline limestone, gneiss, schists. With garnet, tourma- line, chondrodite, wollastonite, epidote, pyroxene.
White C— Pinacoidal
Yellowish white F — Conchoidal Brittle
In basic rocks — basalts, traps; crystallioe limestones. With augite, magnetite, spinel, plagio- clase, chromite, pyrope.
C — Dodecahedral, i ally indistinct
F— Conchoidal, une Brittle
Groaaularile, in crystalline lime- stones and dolomites, with wol- lastonite, vesuvianite, diopside, Bcapolite; uvarovite, in serpentine, with chromite, or in crystalline limestones; andradite, with feld- spar, nephelite, leucite, epidote, magnetite.
White
C— Indistinct F— Conchoidal, con- spicuous Brittle
Characteristic conchoidal fracture and glassy luster. Chloritic
rite; cat's eye, opalescent, due to included fibers of asbestos; atne- Ihyst, purple or blue violet, usu-
ally in crystals.
White
C— Indistinct
F— Conchoidal, con-
spicuous Brittle to tough
Not as glassy as phanerocrystal- line varieties. Chalcedony, chryso- 'prase, prate, plasma, uniform in color; heliotrope, spotted. To
White
C— None
F — Uneven, conchoi-
compact masses resemble fine
dal
grained marble. With gypsum.
Brittle
anhydrite, halite, camallite.
ijGoogle
B. HIHERALS WITH IfOH-BIETALUC LUSTER
Streak
— Uncolored, white, or light gray
Crystallisation
Name, Composition, and
Structure
Luster
Color
References
Crystals Massive 'M
Transparency
loUte (Cordierite)
Orthorhombic
Vitreous
Light blue
C — Short prismatic,
Dull
Violet blue
(Mg,Fe).A].(OH),(Si,0,).
Transparent to
Smoky blue
H — Compact.dissemi-
translucent
Greenish blue
nated, granular
Knua. DanA, Psro<
23B, 407, 384
Tourhalihe
Hexagonal
Vitreous
Green
C— Prismatic, vertieaUy
Transparent to
Blue
M,'A],(B.OH)i.O„
striated; terminated
M'-Na,K,Li,Mg,Fe
with brolfen or rhom- bohedral-like surfacea
1B3. M7, 409
Hexagonal
BERYL, varietiee
Vitreous
Pale green
Emerald
C— Long prismatic, often
Transparent to
Emerald green
Be,Al,(SiO. Aquamanne
verticaDy striated,
translucent
Bluish green
Common
large M— Columnar, granular, compact, rounded pebbles
Sky blue
257. 405. 391
Cubic
Vitreous
Grass greeu
ChloTOspinel
C— Octahedral, usually
Dull
Dark green
R"(R"'0,), Pleonaste
well developed
Translucent to
Grayish green
R"=Mg,Fe GahniU
M— Compact, granular,
opaque
Light blue
Zn.Mn Blue spinel
disseminated grains
Orthorhombic Vitreous Pale blue
C — Prismatic, vertically Transparent to Bluish green
striated, highly opaque Light green
modified H — Compact, granular,
rolled fragments
:y
3. Greev, Blub, Or Blue Violet In Color
Cleavage -C Fracture -F
Tenacity
Gravity
C — Pinacoidal, some- times conspicuous
F — Conehoidai, v
Brittle
C — Indistinct F — Conehoidai, u Brittle
When fresh, glassy and hard, re- sembling blue quartz; usually altered, then dull and softer. Transparent varieties may show pronounced dichroiam macro- scopically. With quartz, feld- spar, hornblende, silUmanite, andalusite.
Spherical triangular crosH-section. With zonal distribution ot color — green, red, colorless. In igneous and metamorphic rocks. With lepidolite, feldspar, quartz, bio- tite.
Crsrstals usually simple — prism and base. Emerald, transparent and emerald green; oquamaHne, transparent, bluish to sea green or yellowish green. In granitic rocks, mica schists, clay slates, placers. With quartz, feldspar, mica, topaz, tourmaline, cassiter- ite, chrysoberyl, garnet.
White
C— Octahedral,
indis-
Commonly as contact mineral in
Grayish
tinct F— Conehoidai Brittle
granularlimestonea; in more basic igneous rocks; rounded grains in placers. With calcite, chon- drodite, serpentine, brucite, corundum, graphite, pyroxenes.
C — Basal, usually c
spicuous F — Conehoidai, une' Brittle
Crystals usually developed on one end only. Color may fade on exposure. In veins and cavities in granitic rocks; alluvial deposits. With cassiterite, tourmaline, apatite, beryl, scheelite, wol- framite.
:y
B. MMEHALS WITH HOIT-METALLIC LUSTER Strettk~-tTiicolored, white, or light gray
CrTBtalliiatioD Structure CryBtftla-C Massive - M
Transparency
Cbrysoberyl, varieties
Ordinary Be(A10,), Alexaitdriie
KrauB, DsOK.
Orthorhombic Vitreous Light green
C— Tabular; heart-shap- Greasy Yellowish
ed, paeudohexagonal Transparent to green
twins translucent Emerald
H — Compact; loose,
' rounded grains i
CORUHDUH, varieties Sapphire AljO, Oriental emerald
Oriental amethyst Cojnmon
Hexagonal
C — Prismatic, tabular, pyramidal, rhombo- liedral; rough or rounded barrel- shaped H — Compact, granular, lamellar
Vitreous Green.
Transparent to Blue opaque Blue violet
:y
3. Oreeh, Blue, Or Blue Violet Ih Color
Cleavage
Fracture— F Tenacity
Characteristics and AsBociates
Cryatala disaeminated as plates with feather-Uke or radial stria- tions. AlexaTtdriie, red in trans- mitted light; cat's eye, opaleecent. In mica schiat, Jeisa, granite; also in placers. With beryl, gar- net, tourmaline, sillimanite.
C — None; nearly rec- tangular basal and rhombohedral part- inga, conspicuous; often Htriated
F — Conchoidal
Brittle to tough
When maBaive, often multi-colored — red, gray,, yellow. Sapphire, transparent, blue; oriental emer- ald, green, transparent; oriental amethyst, violet. In limestone, granite, ayenite, schist, perido- tite; placers. With magnetite, nephelite, mica, chlorite, spinel.
:y
B. Uherai With Hoh-Metallic Ldster
Streak — Hed, brown, yellow, or black
CrystalliiatioD Structure Crystals Massive
' Transparency
Bauxite A1,0(0H),
Never in crystala M — Pisolitic, oolitic, round disseminated grains, clay-like,
earthy
Knus, Dana, Pftnooa 94, 350, 34S
Dull
Earthy Opaque
Yellow Yellowish
brown
Lxhohite, V
Yelhiv oeher
Fe.O,{OH), Brown oeher
Bog iron ore
Broum day
irotalone
—Earthy, porous, clay- like, oolitic, pisolitie
Earthy
Dull
Opaque
YeUow Yellowish brown Dark brown
Wad
MnO„ H,0, etc.
Amorphous T
Dull
Brown
M— Earthy,
metimes
Blackish brown
with globular
Opaque
structure
MoDoclioic
Greaay
Lemon yellow-
C— Rare
Pearly
M— Foliated,
granular,
Translucent
reniform,
fibrous.
crustB
Monoclinic
Resinous
Reddish yel-
Transparent to
low
M— Compact,
granular,
translucent Greasy
Orange yellow-
Orthorhombic
Straw yellow
C— Pyramids
tabular
Honey yellow
M~Granular,
fibrous
Translucent
Brownish
earthy, crusts, com-
yeUow
pact
Reddish yellow
ijGoogle
4. YELLOW OR BSOWH IN COLOR Hudness 1 to 3
Cleavage Fracture -F Tenacity
Specific i Gravity
Color and streak variable, due to pigments. Clay odor, when breathed upon. Commonly with pisolotic or oolitic structure. With clay or kaolinite, in nodules, grains, or irregular ma.iRes in limestone or dolomite.
Yettoiv ocher, earthy, and yellow, when impure gritty; brown ocher, earthy and brown ;6oj iron ore, porous; bromn clay ironstone, massive or concretionary, impure from clay, saod. Ocherous varieties may soil fingers.
Very soft varieties soil fingers. Apparently very light and floats on water, due to porosity; usually adheres to tongue. With pailom- elane, rhodochrosite, pyro- lusite, limonite.
Lemon yellow
C— Clinopinaeoida 1 , usually conspicuous
Slightly sectile, laminie flexible
Orange yellow
C— Clinopinaeoida 1,
basal, not conspic-
F— Conchoidal Slightly sectile
Pale yellow
C— Indistinct F— Conchoidal Brittle
Characteristic lemon yellow color. Frequently disseminated in clay or dolomite. With realgar, stib- nite, barite, calcite.
Redder in color than orpiment. Diaseminatd in clay or dolomite. With orpiment, stibnite, native arsenic, pyrite, barite, calcite.
Independent beds in gypsum, limestone; in lava, result of vol- canic exhalations. With celes- tite, anhydrite, aragonite, clay, metallic sulphides.
:y
B. imiERALS WITH HOII-MBTALLIC LUSTER
Streak— Red, brown, fcUow, or black
CrTstallization Structure Crystals -C Massive— H
Traospareocy
Copiapite (Miey)
Monoclinic
Pearly
Sulphur
C— Tabular, six-sided.
Dull
yellow
Fe,(Fe.OH),(SO,)
,,18H,0
rare
Translucent to
Greenish
Mow.
H — Granular, scales,
opaque
yellow
Kiaua
niimi
Panon
„ powder
Brownish
S35.
yellow
*CIimABAR
Hexagonal
Dull
Reddish
AdaDiantine
brown
HgS
thick tabular, rare M— Fine granular, fibrous, earthy
Translucent to transparent
52,
293,
34
coatings
♦Olivenite
Orthorhombic
Vitreous
Brown
C— Priematic, acicular
Dull
YeUow
Cu(Cu.OH>AsOj
M— Renitorm, fibrous, . with velvety surface;
Transparent to opaque
504,
earthy
Wulfenite
Tetragonal
Greasy
Wax yellow
C— Square, thin tabular;
Adamantine
Orange yelloB
PbMoO.
more rarely pyrami- dal
Transparent to translucent
Brown
641,
H— Coarse, fine grained
Vanadinite
Hexagonal
Greasy
Straw yeUow
C— Prismatic, Bmatl, at
Translucent to
Brownish
Pb.Cl(VO.),
times skeletal H — Compact, globular.
opaque
yeUow
soo.
2S4
fibrous, crusts
brown
Streak — Red, brown, yeUow, or black
Hexagonal
C— Small, rare
H — Earthy coatings
Adamantine Honey yellow Greasy Orange yellow
Translucent Greenish yellow
:y
1.6 Yellowish
4. Yellow Oh Brows Hi Color
Hardness 1 to 9
Cleavage Fracture — P Tenacity
C— Pinacoidal F — Earthy, scaly Brittle
Disagreeable metallic taste. Oxi- dation product of iron sulphide minerals — pyrite, marcasite, pyirhotite.
Reddish brown C — Prismatic, not conspicuous F — Uneven Brittle to sectile
Dark color and streak due to impurities. High specific grav- ity often reduced by gang lie. Dissemioated in silicious rocks. With native mercury, pyrite, marcasite, realgar, stibnite.
Some varieties soil finers. Diver- gent, fibrous structure, and vel- vety surface important. With copper minerals.
Lemon yello\ Pale yellow
Square plates, sometimes with forms of the third order. With lead minerals — galena, pyromor- phite, vaoadinite.
C— None
F— CoDohoidal, i
Crystal faces smooth with sharp edges. With lead minerals, but never in large quantities.
Hardness over 3
—Prismatic, basal, not conspicuous
Usually as bright yellow powder on sphalerite. With smithsonite, prehnite, galena, calcite.
ijGooglc
B. MINERALS WITH HOIT-METALLIC LUSTER Streak — Red, brown, jrellow, or black
Crystallization
Name, Compoeition, and
SUucture
Luster
Color
References
Crystals -C
Transparency
Massive -M
LmOHITE, varieties
C — Always pseudo-
Metallic
Yellowish
Compact
morpha, commonly
Dull
brown
Bog I
ran ore
after pyrite, marca-
Opaque
Dark brown
Fe,0,(OH).
Brown clay ironstone
site, Biderite M— Compact, atalactitic,
botryoidal, nodular;
often with internal,
Moeea
radial fibrous struc-
Kraus
Dstiii,
and
ture; porous, pisoli-
S5.
tic, oolitic
Siderite
Hexagonal
Vitreous
C— Rhombohedral,curved
Pearly
Reddish
FeCO,
or saddle-shaped
DuU
brown
M— Cleavable, granular,
Translucent
Dark brown
compact, botryoidal.
to nearly
118,
35S,
rarely fibrous
opaque
Halerite
Cu"bic
Greasy
HoneyyeUow '
C— Tetrahedral, common
Submetallic
YeUowish
ZnS
M-Cleavable, fine or
Transparent to
brown
coarse grained,
opaque
Reddish
compact
brown
Pyromorphite
Hexagonal
Greasy
Wax yellow
C— Prismatic, thick
Adamantine
Green yellow
Pb,Cl(PO.).
tabular, rounded
Yellowish
and barrel-shaped
opaque
brown
acicular
M — Globular, reniform.
172,
disseminated, crusts
'Zincite
Hexagonal
Adamantine
Orange yellow
C— Small, rare
Vitreous
Reddish
ZnO
M— Compact, granular, foliated
Translucent to
opaque
yellow
Xenotime YPO,
Tetragonal Greasy Yellowish
C — Pyramidal, prismatic Vitreous brown
H — Compact, dissemi' Translucent to Reddish nated, rolled grains opaque brown
Pale yellow
:y
4. YELLOW OR BROWH IN COLOR Hftrdness over 3
Hard-
Streak
Cleavage -C Fracture -F Tenacity
Specific Gravity
Characteristics and
Associates
YeUowish
F— Conchoidal, splin-
browa
tery, earthy Brittle
face and passing into soft, yellow 00 hgrous variety. Compact limon- ite, massive with fibrous struc- ture, rather pure; bog iron ore,
massive or concretionary, impure from clay, sand.
Pale yellow
Curved crystals and rhombohedral
Yellowish
conspicuous
cleavage characteristic. In ore
brown
F-Conchoidal Brittle
deposits; beds and concretions in limestones and shales. With pyrite, chalcopyrite, galena.
tetrahedrite, cryolite.
Pale yellow
C~Dodecahedral,
3,9
Distinguished from siderite by
Light brown
usually conspicu- Brittle
4,2
crystallization, more greasy lus- ter, and cleavage. Color and streak vary with impurities. Extensively in limestones. With galena, chalcopyrite, pyrite, rhodoehrosite, barite, fluorite.
Yellow
C— None
6,5
Common alteration product of
Greenish yellow
F— Conchoidal, un-
lead minerals. With galena
cerussite, mimetite, barite, limon-
4. Orange yellow 4.5 Reddish yelloi
Basal, sometimes
conspicuous F — Uneven Brittle
C — Prismatic FUneven, splintery Brittle
Recognized by associates. With calcite, franklinite (black), wil- lemite (yellow to green), rhodo- nite (flesh red.) On exposure becomes coated with the white
Commonly as loose, disseminated, or attached crystals resembling zircon but softer. In granite, gneiss, with zircon; alluvial deposits.
:y
B. HUTERALS WITH IfOH-HETALLIC LUSTER
Strak— Red, brown, yellow, or black
CryBtalliiatioD
Structure Crystals— C Massive M
Transparency
Orangite, (Thorite) Tetragonal Greasy Orange yellow
C — Square prisms with Vitreous Brownish
ThSiOj bipytamids Transparent to yellow
Kriiua, Dana, Panons H— Compact, diasemi- translucent Dark brown 80. 430, 254 nated
WOLFRAMITE (Fe,Mn)WO,
Orthorhombic
Adamantine Yellow
C— Small, thin tabular. Dull Yellowish
needle-like; parallelly Translucent to brown grouped or in scaly, opaque Dark brown
fibrous, velvety crusts H — Reniform, stalactitic
Uonoclinic Greasy Reddish
C — Long fibrous, bladed, Submetallic brown
stalky; often diver- Translucent to Hair brown
gent, without good opaque Pale yellow terminations H — Compact, lamellar,
Monoclinic Submetallic Reddish brown
C — Thick tabular, short Opaque Bark brown
columnar, often large H — Bladed, curved lam- ellar, granular, com-
Orthite (AUanite)
Ca,(Al,Ce,Fe),{Al,OH)(SiO.),
Monoclinic C— Tabular, rare M-— Compact, granular, bladed, disseminated
Greasy Dark brown
Submetallic Blackish
Translucent to brown opaque Yellowish
brown
Orthorhombic Adamantine
Only in crystals, — py- Metallic
ramidal (often with Opaque
hexagonal habit),
prismatic, tabular
Uncoinmon color.
ijGoogle
4. YELLOW OR BROWIT Dl COLOR HardneBS over 3
Cleavage Fracture -F Tenacity
Characteriatica a AsBociates
4.6 Light orange CPriematic, no
6. Dark brown conspicuous
F — Concltoidal
Brittle
Yeilow orangite sometimes sur- rounded by dark brown to black thorite, which is thought to be decomposed orangite.
4.5 Yellow
6.6 YeUowiBh
CBrachyjuoaeoidal P — Uneven, splintery Brittle
Usually with other iron minerals; in cavities in hematite or limon- ite. Crystals and cleavage distinguish it from limonite.
C-Clinopinacoidal,
conspicuous Brittle
Structure, cleavage, and high specific gravity characteristic. In quartz veins. With wolfram- ite, fluorite, pyrite, scheelite, galena, tetrahedrite.
Reddish brown Dark brown
C— Clinopinaeoidat,
F— Uneven Brittle
Distinguished from huebnerite by streak. Powder may be slightly magnetic. With cassiterite, quartz, mica, apatite, soheelite,
Pale brown Grayish brown
C -Indistinct
al Brittle
Often covered with yellowish or
DiHseminated in acid igneous rocks; also in limestones. With magnetite, epidote, quartz, (eld- spar.
Yellowish Brownish
C— Indistinct F— Uneven Brittle
Crystals may be striated; not twinned Uke rutile. With ana- taee, titanite, rutile, adularia.
ijGooglc
B. HniERALS WITH nOH-HETALLIC LUSTER
Streak— Red, brown, yellow, or
blACk
CryetalluatioD
and
Structure
Luster
Color
ReferenceB
Crystals -C Massive -M
Transparency
Rotile
Tetragonal
Adamantine
Reddish brown
C— Prismatic, vertically
Submetallic
Yellowish
TiO, or TiTiO,
striated ; twinned
brown
yielding knee-shaped
opaque
Dark brown
Mosea
or roHette forms
Kiaiu, Dana
PanoD!
M— Compact, dissemi-
nated Tetragonal
CASSrrERITE
Adamantine
Reddish
C— Thick prismatic;
Greasy
Yellowish
SnO, or SnSnO.
knee-shaped twins
Dull
brown
quite common
Translucent to
Dark brown
H — Reniform. botryoid-
opaque
al, rounded pebbles.
often with internal,
radial fibrous struc-
ture.— mood tin
SPIHEL, variety
Cubic
Vitreous
Yellowish
Picoiile
C— Octahedral, small
Dull
brown
(Mg,Fe),(Ai,Cr).0
M— Compact, granular.
Nearly opaque
Greenish Brown
1S7. 338.
Streak-
-Uncolored, white, or Eght gray
CerargTTite (Horn silver)
Cubic
Waxy
YeUowish
C— Rare
Greasy
Brownish
AgCI
M— Wax-like crusts and coatings; stalacritio, dendritic
Transparent to translucent
101. 319,
CanialUte
Orthorhombic
Vitreous
YeUowish
C — Pseudohexagonal,
Dull
MgCl,,KCl,6H,0
rare
Transparent to
106, 323.
H — Compact, granular
translucent
Pjrrophyllile
Orthorhombic ?
Greasy
Brownish
CIndistinct
Dull
YeUowish
H,Ali,0„
M— Radiated fibrous, or lamellar aggregates;
Translucent to opaque
231, 482.
, 423
granular, compact
ijGooglc
4. YELLOW OR BROWH m COLOR Hardness c-ni 3
Cleavage Fracture — F
Tenacity
Specific Gravity
Pale yeUow Pale brown
C— Prismatic, py- ramidal, not conspicuoua
F— Uneven
Brittle
Pale browQ Pale yellow
C— Indistinct F— Uneven Brittle
Characteristics and
Not as heavy as caasiterite. Often in fine hair-like inclusions. With quartz, feldspar, hematite, ilmen- ite, chlorite, brookite.
Recognized by high specific grav- ity. In veins cutting granite, gneiss; in alluvial deposits as stream tin. With quartz, mica, wolframite, arsenopyrite, molyb- denite, tourmaline, fluorlte.
7,6 Pale brown
C- — Indistinct F— Conchoidal Brittle
Commonly in basic igneous rocks, especially olivine- bearing types.
With serpentine, olivine, corun- dum, magnetite, garnet.
1. White, shiny
1.0 Gray, shiny
C— None FConchoidal
Highly sectile
C — Indistinct F — Conchoidal Brittle
Cuts like wax, yielding shiny sui faces; on exposure turns violet, brown, or black. With silver minerals, especially argentite, native silver; also limonite, cal- cite, barite.
Bitter taste. Absorbs moisture. With halite, kieserite, kainite, sylvite, anhydrite.
C — Longitudinal F— Fibrous, uneve Laminee flexible
Soft and greasy like talc, but usually in radiating fibers. In schistose rocks. With cyanite, lazulite, topaz, graphite.
cGoogIc
HOtERALS WITH HON-UETALUC LUSTER Streak — Uncolored, white, or light gray
Name, Composition,
and
Stracture
Luster
Color
References
Crystals -C Massive -M
Transparency
C&lomel
Adamantine
YeUowish
C— Tabular, pryamidal.
Translucent to
Brown
H?,C1,
small
Mwea
H— Coatings
opaque
Kiaua, Dans
Paraona
106, 317
TRIPOLrTE (Opal)
Amorphous
Vitreous
YeUow
M— Porous, earthy, chalk-
Dull
Yellowish
8iO,,xH,0
like
brown
8S. 329
opaque
Brown
Monoclinic
DuU
Yellowish
C — Scaly, hexagonal or
Pearly
H.Ali,0.
orthorhombic out- Une, rare M— Compact, friable.
mealy, clay-like
Earthy Opaque to translucent
230, 481
TALC, variety
Monoclinic
Greasy
Yellowish
Soapatone or
atealite
M— Compact, globular.
Peariy
YeUowish
H,Mgi.O„
granular
Translucent to opaque
brown Browniah
227, 479
m
Asbestos, variety
Orthorhombic ?
Silky
Yellowish
ChryfotUe
M— Fibrous, coarse or
Greasy
Brownish
H,Mg,8i,0,
fine; felted
Opaque
220, 474
variety
Monoclinic
Silky
YeUowish
AmphiboU
M— Fibrous, coarse or
Dull
Brownish
Silicate of Ca, Mg, Fe,
Al, etc.
fine; felted; compact, leather- or cork-like
Opaque
263, 0I
ijGoogle
4. Yellow Or Browh Is Color
HardoeBS 1 to 3
Cleavage — C Fracture Tenacity
Characteristics and
White Gray
C — Indistinct F — Conclioidal Very sectile
Cliaracterized by high specific gravity and associates. With mercury minerals — cinnabar, na- tive mercury; barite, quart*, tetrahedrite.
1. White 2.e Gray
1. White C— Basal,
2.6 Yellowish white P— Earthy Brittle
Apparently very soft, but fine particles scratch glass. Resem- bles kaolinite, but gritty and not plastic.
Not gritty like tripolite. Very strong clay odor when breathed upon. Usually adheres to tongue and becomes plastic when moistened. Greasy feel. With quartz, feldspar, corundum, dia- Bore, topas.
2.6 Greasy or soapy feel important.
2.8 SoapsUme or sUatiU, coarse to fine granular, more or less im- pure. Hardness varies. With serpentine, chlorite, dolomite magnesite, actinolite.
1 . Delicate, fine, parallel, flexible
2 . 5 fibers, easily separable, Aori
fibered asbesloi, compare below.
In veins or seams in compact
serpentine.
F— Fibrous Flexible, tough
Long fihered asbestos, parallel, flexible fibers. Compare above. Mountain leather, mountain eork, mountain wood, compact but light and tough.
:y
B. HnmRALS WITH ITOH-HETALLIC LUSTER
Streak— Dncolored, white, or gray
Crystal Usatioi Structure Crystals Massive M
Transparency
Sal Ammoniac NH.Cl
C — Distorted, rare H — Fibrous, powdery, stalactitic, crusts
Vitreous Yellow
Trausparent to Yellowish translucent brown
Stnivite
NH,MgP0,.6H,0
Orthorhombic CDomatic, hemi-
morphic M — Granular, earthy
♦SODA HTIER (Chile saltpeter) Hexagonal C— Rare NaNO, H— Granulai
517,
GYPSUli varieties
Selenite CaSOj,2HjO Satinspar Ordinary
Vitreous Brownish
DuU Yellowish Translucent to
opaque
Vitreous Yellowish
Transparent Lemon yelloir Reddish brown
Pearly Yellow
Vitreous Honey yellow
Silky Brown
Dull
Transparent to opaque
Adamantine Straw yellov
Greasy Brownish
Translucent yellow
Reddish
yellow
Monoclinic
C — Tabular, prismatic; swallow tail twins
M— Cleavable, coarae and fine grained, fibrous, foliated,
Orthorhombic
C— Pyramidal, tabular
H — Compact, granular,
fibrous, earthy,
crusts
Cubic Vitreous Yellow
C — Cubes, alone or with Transparent to Reddish
octahedrons, rare translucent yellow H — Granular, compact
HALITE (Rock salt)
Cubic Vitreous Yellow
C — Cubes, often skeletal Transparent to Yellowish
or hopper-shaped translucent brown
M— Compact, cleavable, Brownish
granular, fibrous,
stalactitic, crusts
:y
4. YELLOW OR BROWH m COLOR Hardness 1 to 3
Cleavage
Streak
Fracture -F Tenacity
White
C— Octahedral, indis- tinct F— CoDchoidftl Brittle
White
C— Pinacoidal
Brittle
White
C— Rhombohedral
F— Conchoidal Brittle
White
C — CI inopinacoidal,
conspicuous; py- ramidal, orthopina- coidal F — Conchoidal, fibrous Brittle, lamins flex-
Specific Gravity
1.5 White C— Indistinct
2.6 Yellowish white F— Conchoidal
Brittle
C— Cubic F— Conchoidal Brittle
C — Cubic, perfect,
conspicuous F — Conchoidal Brittle
Pungent, salty taste, somewhat astringent. Usually sublimation product. Near volcanoes, burn- ing coal beds, guano deposits.
Crystals coffin-shaped with pro- nounced hemimorphiam. In sewers, vaults, guano deposits.
Cooling and saline taste. Absorbs moisture readily. In deposits with gypsum, sand, clay, guano.
Selenite, crystals and cleavable plates, usually transparent; atin spar, fibrous with silky luster; ordinary, granular. In lime stones and shales. With halite, celestite, sulphur, aragonite, anhydrite; ore deposits.
Independent beds in gypsum limestone in laa result of \ol came exhalations W ith ceies tite anhydrite aragonite clay metallic sulphides
Color due to impurities baity bitter taste May absorb mois ture and become damp In salt deposits With hahte kainite cirnalhte
Pigment usually iron oxide May absorb moisture and become damp Characteristic cubical cleavage and sahne tiste With shale gypsum anhydrite pol>
:y
B. BDHERALS WITH IfOH-HBTALUC LUSTER Streak — Dncolored, white, or Ugbt gny
CrystalliBfltion
Structure
Luster
ReferenceB
Crystals -C Massive -M
Transparency
Paragonite
Monoclinic
M — Compact, fine scaly
Pearly Translucent
Yellowish
H,NaAl.(8iO.).
aggregates
Eraiu, Dana.
219. 4St.
MOSCOVirE (Isinglaa
s)
Vitreous
Light yellow
C — Tabular, pyramidal,
Pearly
Yellowish
H,KAl.(8iO.),
with orthorhombic
brown
or hexagonal outline;
translucent
Light brown
often large and rough
y
Mcales, plates; toU-
ated and plumose
217. 464,
aggrfgatee
Pearly
Yellow
C— Prismatic, tabular,
SubmetaDic
Yellowish
(K,H),Mg,Al(SiO.)
with hexagonal or
Transparent to
brown
orthorhombic outline;
translucent
Brown
often large and
M— Plates, disseminated
scales
217. 469.
APATITE, variety
Phosphate rock Ca(PO.) chiefly
170. 487. 330
Hexagonal
M— Compact, fibrous,
nodular, reniform,
earthy
DuU
Opaque
Brown
FeSiO,
2S3. 401.
Monoclinic
C— Fine, acicular
H— Fibrous, lamellar
SUky
Translucent to opaque
Brownish
Glsuberite
NaO.,CaSO.
132, fl23, 314
Monoclinic
C— Thick tabular
H— Reniform, lamellar
Greasy Vitreous Transparent to
Pale yellow YeUow
LeadhiUite
PbS0.,2PbC0,.Pb(0H),
145. 528.
Monoclinic
C— Tabular, pseudohex-
agonal; twins and
trillings M— Compact, lamellar
Greasy
Transparent to
YeUow Brown
ijGoogle
4. YELLOW OR BHOWH ffl COLOR
Hardness 1 to 3
Cleavage — C Fracture — F Tenacity
C — Basal, perfect F — Scaly, granular Tough
Distinguished from other micas
by associates — cyaDtte, stau ro- ute, tourmaliDC.
C — Basal, perfect,
conspicuous Tough, laminie very
elastic
C — Basal, perfect, conspicuous
Tough, lamina very elastic
Lighter colored than phlogopite. Structure, perfect cleavage, and elasticity important. Crystals may show distinct partings per- pendicular to cleavage — ruUd mica. In granitic rocks, schists, limestones. With feldspar, quartz, tourmaline, beryl, garnet.
Usually amber brown or bronie in color. When cleavage lamina are held close to the eye in view- ing a source of light a star-like form is sometimes observed. Especially characteristic of crys- talline limestones, dolomites, schists. With pyroxenes, am- phiboles, serpentine.
White White
F— Conchoidal, Brittle
nn- 3
More or less impure masses, fre- quently resembling compact
nodules, concretions.
S.
C— Fibrous Brittle
Usually with quarti, magnetite, scAtrt.
White
C— Basal
F— Conchoidal Brittle
Bitter, saline taste. On exposure becomes coated with white powdery crust. With halite, thenardite, mirabilite.
White
C— Basal, perfect P— Conchoidal, ra
observed Rather sectile
rely 6
Soft and very heavy. Twins and trillings resemble those of arago- nite. Sparingly with lead min-
calcite, galena.
ijGoogle
B. Hiherals With Koh-Metallic Ldster
Strfeak — Uncoloied, white, or Ught gray
Cryatallizatioi Structure Crystals — C Massive— M
Transparency
Amber (Succinite)
Amorphous
Greasy
Light yellow
H — Irregular, atalactitic,
Honey yellow
C.,H,.0.
. grains, lumps
translucent
Bronnisb
yellow
KrauB, Dans.
290. 543.
Kainite
Monaclinic
C— Tabular, prismatic,
Vitreous Transparent to
Yellow
Mg80,.KC1.3H,0
rare M— Compact, fine
translucent
154, 630.
grained
Gibbaite (HydrargilUte)
Monoclinic
C— Pseudohexagonal,
Vitreous Pearly
Yellowish
Ai(Oh),
tabular, rare M— Stalactitic, mammil- lary, surface smooth, internal structure fibrous; scaly aggre-
Translucent
92. 351,
gates
Cryolite
Vitreous
Grayish
C— PBCudocubical, small.
Greasy
brown
AIF,.3NaF
M— Cleavable, compact, granular
translucent
Dark brown
Orthorhombic
BARITE (Heavy spar)
Vitreous
YeUowish
C— Tabular, prismatic.
Pearly
Brownish
BaSO.
very common; crest- ed divergent groups M— Compact, lamellar, fibrous, cleavable.
Transparent to opaque
Dark brown
135, 624.
31B
reniform
Amorphous
Vitreous
Brown
M— Reniform, mammil-
Greasy
Yellow
AliO. 5H,0
lary, stalactitic, in-
Translucent
287. 485,
Monoclinic
Kieserite
Vitreous
Yellow
C— Pyramidal, rare
Transparent to
MgSO,.H,0
H — Compact, granular
translucent
140, 531.
Vnconuuon color.
ijGoogle
4. Yellow Or Browh Ih Color
Cleavage — C Fracture -F
Tenacity
Specific Gravity
Characteristics and
Fossil resin. Electrified rubbed. Often mottled
striped. Sometimefi with inclu' aions — ineectB, vegetabli Uquids, minerale.
2.S
White
C— Pinacoidal, pris-
2. '
Taste, saity, bitter and astringent.
matic, not con- spicuous F— Uneven
Brittle
Non-hygToBcopic, With halite, sylvite.
White
C— Indistinct
2,3
Strong clay odor when breathed
Tough
2,4
upon. With bauxite, natrolite, Hmonite, corundum.
2.S
White
2,9
Often contains disseminated
perfect, nearly at
conspicuous F — Uneven Brittle
siderite, chalcopyrite, galena, pyrite, fluorite, coiumbite.
White
C— Basal, prismatic.
Characterized by rather high
usually conspic-
F— Uneven Brittle
4,7
specific gravity and cleavages. In metalliferous veins ; pockets, lentic-
galena, sphalerite, fluorite, chal- copyrite; manganese and iron minerals.
White
F-Conchoidal,
earthy Brittle
1,9
Structure resembles opal. In fis- sures and cavities with iron and copper minerals.
White
C— Pyramid
2,5
Due to absorption of water,
F— Granular
2,6
becomes coated with white crust
Friable to firm
of epsomite. With halite, po-
ijGoogle
B. Bokerals With Moh-Hetallic Luster
Streak
— tlncolored, white, or light gray
CrystaUiuUoo
Straetiire
Luater
HeicFnccB
Crystals -C Massive -M
Transparency
CALCITE, varieticH
HexBKoaat
Vitreous
Honey yeUow
Dog tooth spar
C— Scalenohedral, rhom-
DuU
Yellowish
CaCO, Nail head ipar
bohedral, prismatic;
Transparent
brown
AnikTaamiie
tabular, acicular;
to nearly
Dark brown
Ltmentone
may be highly modi-
opaque
Marble
fied and twinned
TraverHne
H — Cleavable, granular,
fibrous, banded, stal-
ThinolUe
actitic, oolitic, por-
ous, compact, crusts,
KraiB. Dsna, Panmn,
shells.
Wulfenlte PbMoO.
Tetragonal Greasy Wax yellow
C— Square, thin tab- Adamantine Orange yello
ular; more rarely py- Transparent to Brown
ramidal translucent
H — Coarse, fine grained .
Hexagonal
C— Prismatic, small, at
times skeletal H— Compact, globular,
fibrous, crusts
Greasy Straw yellow
Translucent to Brownish opaque yellow
Reddish
Streak — Cncofcired, white or light gray
*6ibbsite (Hydrargillite)
Polyhalite
K,MgCa,(
Monoclinic
Vitreous
Yellowish
C — Pseudohexagonal,
Peariy
tabular, rare
Translucent
M— Stalactitic, mammil-
lary, surface smooth.
internal structure
fibrous; scaly ag-
gregates
Monoclinic 7
Greasy
Yellowish
C— Indistinct
Pearly
M— Compact, fibrous.
lamellar
ijGoogle
4. YELLOW OR BROWH m COLOR
HaidjiMs 1 to3
Cleavage - Fracture — Tenacity
Characteristics and AsBociatea
-— Rombohedral, usually eonspicu-
Often in extensive deposits. Rhombobedial cleavage charac- teristic eapecialiy on crystals. Cleavage surf aces often striated. Very strong double refraction easily observed when transparent. To distinguish varieties, see references.
Whit* C — Pyramidal, indis-
Yeliowish white tioct
F— Conchoidal, un-
Square plates sometimes with forms of the third order. With lead minerals — galena, pyro- morphite, vanadinite.
Crystal faces smooth with sharp edges. With lead minerals, but never in large quantities.
Hardness 3 to 6
C— Indistinct Tough
Strong clay odor when breathed upon. With bauxite, natrolite, limonite, corundum.
Taste, bitter and astringent, but weak. With halite, anhydrite, 1, clay.
:y
HnrERALS WITH HOH-HETALUC LUSTER Streak — Uncolored, white, or light gray
Crystallizatiol Structure Cryatala-C Klussive - M
E Orthorhombic
C— Tabular, priBmatic, common; pyramidal HoMB H— Compact, cteavable, . Dana. PaSona fibrous, granular,
134, 626. 321 reniform
Transparency
Vitreous Yellow
Pearly Yellowish Transparent to white translucent
*BARITB (Heavy spar)
Vitreous
Yellowish
C— Tabular, prismatic,
Pearly
Brownish
BaSO,
Transparent to
Dark
ed and divergent
opaque
brown
groups
H — Compact, lamellar,
fibrous, cleavable,
135. 524.
reniform .
♦Ahglesite
Orthorhombic
Greasy
Yellow
C— Prismatic, tabular,
Adamantine
Brown
PbSO.
pyramidal M— Compact, granular, nodular
Transparent to opaque
137. 627,
2se
*Cerdssite
Orthorhombic
YeUow
C— Tabular, prismatic.
Greasy
Yellowish
PbCO,
pyramidal; pseudo- hexagonal; clusters and etar-shaped groups M— Interlaced bundles, granular, stalactitic,
Silky ,
Transparent to translucent
brown
122. 363.
compact
Heulandite
Vitreous
Brown
C— Tabular, striated
Peariy
Yellow
(Q
H,CaAl,{SiO,),.3H,0
H — Foliated, granular,
Transparent to
STHiBITE (Desmine
globular
S
s
Vitreous
Yellowish
C— Twinned, sheaf-like,
Pearly
Yellowish
N
{Ca,Nas)Ali,0„.
6H0
radial, or globular
Transparent to
brown
aggregates
Brownish
283. 456.
ijGooglc
4. Yellow Or Browk Dt Color
Hardness 3 to 6
Cleavage Fracture -F Tenacity
Specific
C — Basal, prisma tic,
conspicuous F — Uneven
Brittle
Prominent cleavages. Heavier than calcite, lighter than barite. In limestneB, dolomites, shales. With sulphur, gypsum, aragonite, halite, galena, sphalerite.
—Basal, prismatic, usually conspicu-
F— Uneven Brittle
Characterized by rather high speciRc gravity and cleavages. In metalliferous veins; pockets, lenticular masses in limestone. With galena, sphalerite, fluorite, chalcopyrite; manganese and iron minerals.
C — Basal, prismatic F— Conchoid al Brittle
Adamantine luster and very high specific gravity important. Dis- tinguished from cerusaite by absence of twins. Oxidation product of lead minerals. Usu- ally in cracks and cavities. With galena, cerussite.
White
C— Indistinct
Twinning, structure, luster, and
Gray
specific gravity characteristic.
Brittle
With lead mmerab— galena, pyromorphite, anglesite; also
C — Clinopinacoidal ,
perfect FUneven Brittle
C — Indistinct FUneven Brittle
In basic igneous rocks and metal- liferous veins. With chabasite, Btilbite, apophyllite, datolite.
Radial and sheaf-like structure important. In basic igneous rocks and ore deposits. With heulandite, chabazite, apophyl- lite, datolite, calcite.
jyGoogIc
B. HUfERAIS WITH HOH-BIETALLIC LUSIGR
Streak
-Uncotored. white, or light paj
Structure
Luster
Color
Refereneea
CryrtaU-C Hamive -H
Transparency
Laumontite (Zeolite)
Monodinic
Vitreous
YeDowish
C — ColumnBr
Dull
Brownish
Ca(Al,20H),(Si,0.),.2H,0
H— Radial, divergent,
Transparent to
earthy
opaque
Mora
KrauB, Dana,
280, 467.
SESPEHTinE
Orthorhombic ?
Greasy
Greenish
C— Unknown
Waxy
brown
H,Mgi.O.
H — Compact, columnar,
Translucent to
Greenish
fibroua, lamellar,
opaque
yeUow
granular
Yellowish
229. 478.
brown
Monoclinic
C— Six-sided scales.
Pearly Vitreous
YeUowish
H,CaAli,0„
plates H— Scaly, platy; foliated,
221. 470.
granular aggrctes
APATITE, variety
Hexagonal
Dull
Brown
PkoaphaU rock
M— Compact, flbrous,
Opaque
CaCPOJ chiefly
nodular, reniform
170. 497,
WavelUto
Orthorhombic
Vitreous
Yellow
C-Capillary, smaU
Translucent
Brown
(Ai,0H),(P0.),.5H,0
M— Crusts, globuUr, hemispherical aggre- gates, with radial fi-
180, 812,
brous structure
DOLOJnTE
Hexagonal
Vitreous
YeUowish
Transparent to
brown
CaMg(CO.).
- curved surfaces H — Coarsely crystalline, compact, granular.
translucent
Grayish brown Dark brown
115, 357,
friable
Unoommon color.
ijGoogle
1. Yellow Or Browh Dt Color
Hardness S to 6
Cleavage Fracture "F
Tenacity
Specific
Gravity
Clndistinct
F — Uneven, earthy
Brittle, friable
On exposure becomes dull and crumbles to powder. In cavities and fisBuiea in basic igneous rocks. With atilbite, analcite. apophyllite, native copper.
F — Conchoidal, splin
tery Brittle
Smooth and greasy feel. Oftn spotted, clouded, multiHiolored.
Sometimes crossed by seams of asbestos (chrysotile). With magnesite, chromite, gamierite, pyrope, platinum, calcite.
C — Basal, perfect, conspicuous
F— -Scaly, granular Brittle
Resembles the micas in structure and cleavage, but harder; lam- ins brittle and inelastic. With chlorite, emery, diaspore, conin-
F— Conchoidal, Brittle
More or less impure masses, fre- quently resembling compact, brown limestone. Independent beds, nodules, concretions.
CKnacoidal,
domatic F — Uneven, fibrous Brittle
Secondary mineral occurring on surfaces of rocks or minerals, as crystalline crusts with pronounced radial fibrous structure.
White
C— Ehombohedral,
Gray
perfect (crystals)
F — Conchoidal
Brittle
Crystals generally curved or sad- dle-shaped. Marble includes some compact varieties. Inde- pendent beds; in fissures and cavities; with ore deposits.
:y
B. UKERALS WITH ITOH-METALUC LUSTER StreakDncolored, white, or light gray
AKAGOniTE
CaCO,
*Scorodite FeAsO. 2H,0
STROmTANITE
SrCO,
SmERITE FeCO.
CrystailiMtion
nd Structure
Color
Crystals -C
Transparency
! Massive -M
Orthorhombic
Vitreous
Wine yelk
C — Chisel- or spear-
Resinous
YeUowish
Transparent to
brown
agona) pnsins;
translucent
Mosea acicular aggregates
Pam M— SUlactitie, reniform,
332 crusts, oolitic
Pyrohorphite
Pb,Cl(PO.),
Uncommon color.
Orthorhombic Vitreous
C— Prismatic, pyramida!, Greasy
dnisy Translucent H — Botryoidal, fibrous,
Orthorhombic
Vitreous
YeUow
C— Spear-shaped, colum-
Greasy
Yellowish
nar, acicular; often
Transparent to
brown
in divergent groups
Brown
H — Granular, compact,
botryoidal, fibrous
Hexagonal
Vitreous
Light brown
Pearly
Reddiah
curved or saddle-
Dull
brown
shaped, common
Translucent
Dark brown
H — Cleavable, granular.
to nearly
compact, botryoidal,
opaque
rarely fibrous
Cubic
Greasy
Honey yellow
C— Tetrahedral, common
Yellowish
M— Cleavable, fine and
Translucent to
brown
coarse grained, com-
opaque
Reddish browi
pact
Hexagonal Greasy Wax yellow
C — Prismatic, thick tab- Adamantine Greenish
utar, rounded and Translucent to yellow
barrel-shaped; actcu- opaque Yellowish
lar brown H — Globular, reniform, disseminated, crusts
:y
4. Yeixow Or Browit Is Color
HardneBB 3 to 6
Cleavage — C Fracture -F Tenacity
Characteristics and Asaociates
C— Pinacoidal, pris-
2,9
Twins common, often pseudohex-
Gn.y
matic F— Conchoidal Brittle
agonal— prism and striated base. In cracks and cavities; with ore deposits; deposition from hot springs; in shells. With gypsum, celestite, sulphur, siderite, zeo- lites.
White
C— Indistinct
Grayiflh Brownish white
F— Uneven, conchoid- al
Brittle
ite, pyrite.
3.G
White
C— Prismatic, indis-
Structure similar to aragonite.
Gray
tinct F— Uneven
Brittle
Divergent columnar masses and higher specific gravity character- istic. In ore deposits; independ- ent beds. With galena, barite, calcite.
3.G
Gray
C— Rhombohedral,
Distinguished from sphalerite by
White
conspicuous F — Conchoidal Brittle
curved crystals and rhombohe- dral cleavage. In ore deposits; beds and concretions in lime- stones and shales. With pyrite, chalcopyrite, galena, tetrahe- drite, cryolite.
White
C— Dodecahedral,
Yellowish white
usually conspicu-
F— Conchoidal Brittle
portant. Color and streak vary
limestones. With galena, chalco- pyrite, pyrite, barite, fluorite, rhodochrosite.
3.B White C— None
4. Yellowish white F— Conchoidal, i
Common alteration product of lead minerals. With galena,
ceruBsite, mimetite, barite, limon-
jyGooglc
B. Hdierals With Hoh-Hetallic Lustek
Streak
— Dncolored, white, or light gray
Name, Composition, aad RefereocM
Structure
Crystals -C Massive -M
Luster Transparency
Color
Mimetite Pb.Cl(AsOJ,
173. 600.
Hexagonal
C— Priamatic, tabular,
rounded, barrel-
sh&ped H — Globular, reniform,
crusts.
Greasy
Adamantine Tranalucent
Orange yellow YeUowiah brown Brown
RHODOCHROSITG MnCO,
118, 359.
Hexagonal
C— Rhombohedral, rare
M— Cleavable, granular,
compact, botryoidal,
crusts
Vitreous
Yellow Brown
MAGHESITE MgCO,
116. 358.
Hexagonal
C— Rhombohedral, rare
Vitreous
DuU
Translucent
to opaque
Yellowish Grayish brown
FLTJORITE (Fluor spar) CaF.
. 103. 320
Cubic
C— Cubes, alone or modi- fied, well developed
M— Cleavable, granular, fibrous
Transparent to nearly opaque
Wine
yeUow YeUowish
Brown
*CHABAZITE CaAli,0„.8H,0,
etc
Hexagonal
C— Rhombohedral, cube- like, lenticular M— Compact
Vitreous Translucent to tranaparent
YeUowish Brownish
*Haimol(me
BaAli.0„.6H,0
284. 466.
etc.
Monoclinic
C— Usually twins, pene- trating at 90°
Vitreous Translucent
Yellowish
Brownish
Xenotime YPO.
166. *94.
Tetragonal
C — Pyramidal, prismatic
nated, rolled grains
Greasy Vitreous
opaque
YeUowish brown
Pale yellow
.jGoogle
i. YELLOW OR BROWN IN COLOR
Cleavage —C Fracture — F Tenacity
White
C— Pyramidal, indis-
Yellowish white
tinct F— Uneven
Brittle
as common. With lead minerals —galena, pyromorphite.
White
May turn brown to black on
Gray
conspicuous F-Uneven Brittle
exposure due to MnO,. With ore lena, sphalerite, pyrite, alaban-
dite, psilomelane, silver minerals.
White
C— Rhombohedral
2,9
Conchoidal fracture generally
S.
(crystals) F— Conchoidal, con- . spicuous
Brittle to tough
apparently very hard. In tal- cose and chloritic schists, serpen- tine, gypsum; independent de-
posits.
White
C— Octahedral, per-
3,
Recognized by crystal form.
octahedral cleavage, and hard-
Bnttle
ness. Common gangue of metal- lic ores, especially galena, sphal- erite, caB8itrite; also withcalcite, barite.
White
2,1
Generally in cube-like crystals.
not conspicuous F— Uneven Brittle
Inferior cleavage distinguishes it from fluorite and calcite. In basic igneous rocks. With ana!- cite,stilbite,harmotome,laumonl
White
C— Pinacoidal
ite, heulandite.
Cruciform twins. In basic igneous
Brownish white C — Prismatic Yellowish white F— Uneven, splintery Brittle
rocks and metalliferous veins. With chabazite, calcite, quartt, adularia. PhiUipiite, contains calcium replacing barium. Commonly as loose, disseminated, or attached crystals resembling zircon, but softer. In granite, gneiss, with zircon; also in alluvial deposits.
:y
B. Uherals With Hoh-Icetallic Luster
Streak
CryataUisation
Name, CompOBition, and
Structure
Luster
Color
References
CrystalB -C Massive -M
Transparency
ScheeUte
Tetragonal
Greasy
Pale yellow
C— Pyramidal, small,
Adamantine
Yellowish
more rarely tabular
brown
H — Druay crusts, reni-
translucent
Grayish brown
Kreip, Dam.,
Pa'Sn.
form, granular, com-
139, 540,
33S
pact
WollMtoaite (Pyroxene,
tabu-
Monoclinie
Yellowish
la
spar)
C— Tabular, prismatic
Silky
Brownish
CaSiO.
M— Cleavable, fibrous, granular, compact
translucent
244, 384.
Apatite
Hexagonal
Greasy
Brown
C— Prismatic, thick tab-
Vitreous
Greenish
Ca.F(PO.),
ular, sometimes
Translucent to
brown
large, with rounde<l
opaque
Reddish brown
H— Compact, fibrous.
Yellow
nodular, reniform
170, 487,
ne)
Orthorhombic
HEMIHORPHITE (Calam
Vitreous
Yellow
C— Thin tabular, pyram-
DuU
Yellowish
idal, hemimorphic.
Transparent to
brown
highly modified '
translucent
Brown
M— Compact, globular,
granular, stalactitic,
isa, 446,
cellular, earthy
Huebnerite
Monoclinie
Resinous
Reddish brown
C— Long fibrous, bladed,
Submetallic
Hair
MnWO.
stalky; often diver-
Translucent to
brown
gent, without good
opaque
Pale yellow
terminations
M— Compact, lamellar.
140, 538.
granular
SmTHSOmTE
Hexagonal
Vitreous
Brown
C— Small, usually as
Dull
Yellowish
ZnCOj
druses or crusts
brown
M— Botryoidal, stalactit-
to nearly
Orange
ic, fibrous, compact,
opaque
yellow '
117, 380,
cellular, granular
ijGoogle
4. Yellow Or Brown Ih Color
HardnessS to 6
Cleavage Fracture "F Tenacity
Characterietics and
C — Pyramidal, not
conspicuous F — Conchoidal, un-
C— Basal, orthopina-
coidal, perfect ¥ — Uneven Brittle
Small, well developed octahedral- like crystals, usually on quartz; when massive high specific grav- ity important. With cassiterite, wolframite, fluorite, apatite, molybdenite.
Fibers may be parallel or diver- gent. Typical contact mineral; often in crystalline timestones. With garnet, diopside, veau-viao- ite, graphite.
Crystals may be vertically striated
and have fused appearance.
Color unevenly distributed, often
h g h p In crystal-
m m lliferouB de-
gn ka. With
ss fluorite, wol-
— Prismatic
— Uneven, conchoid-
-like groups
ties. When
B or cellular.
n b sphalerite,
pec lly smithson-
4.6 Greenish gray
C— Clinopinacoidal,
conspicuous Brittle
tenstic. In
W h wolframite,
lite, galena.
White Gray
C— Rhombohed ral,
not often observed FUneven, splintery Brittle
Cellular varieties called dry bone. Often mixed with sand, clay, limonite, calcite. With zinc minerals, especially sphalerite, hemimorphite. Frequently pseudomorphous after oalcite.
ijGoogle
B. HSfERALS WITH NOH-HBTALLIC LUSTER
Streak — Dncolored, white, or light
CiystallizatioQ Structure Crystals Massive — M
Luster Transparency
ralroUte Orthorhombic Vitreous
C — Slender prismatic, Silky
Na,AI(A10){SiO,),.2HjO nearly square, radial Transparent to
Moees or interlacing groups translucent
Kraufl, Dana. Paraons M — Fibrous, granular, 277, 461, 416 compact
o
Orthorhombic
Vitreous
Yellowish
C— Prismatic, vertically
Silky
2(Ca,NaJAl,(SiO.)
striated, divergent
Pearly
5H,0
groups M— Fibrous, columnar, radial; spherical con-
Translucent to transparent
27B, 462.
cretions, compact
Datolite
Vitreous
YeUow
C— Prismatic, pyrami-
Greasy
Brown
Ca(B.OH)SiO.
dal, highly modified
M— Compact, fibrous,
granular, botryoidal
Dull
Translucent to opaque
192. 435,
TITAHITE (Sphene)
Vitreous
Brown
C— Wedge- or envelope-
Greasy
Reddish
iTiSiO.
shaped when dis-
Transparent to
brown
Honadte
{Ce,La,Di)PO,
seminated; tabular opaque Yellow or prismatic when attached H — Compact, lamellar
Monoclinic Greasy Reddish
C — Thick tabular, square Vitreous brown
prismatic Transparent to Yellowish
M — Angular fragments, opaque brown
rolled grains Honey yelloi
Tanciinite Hexagonal
C — Prismatic, rare H,(Na„Ca)(NaCO,Ali,0„ M— Compact, lamellar, columnar, dissemi- 233. 411, 395 nated
♦ Uncommon color.
Greasy Yellow
Vitreous Brownish
Pearly yellow
Translucent to transparent
:y
4. YELLOW OR BROWN IH COLOR Hardness S to 6
Cleavage "C Fracture — F
Tenacity
Speciflc Gravity I
C — Prismatic, perfect Uneven Brittle
Crystals have nearly square cross- section. In basalts and phono- lltes. With chabazit, analcit, apophyllite, stilbite, prehnite, datolite.
C — Pinacoidal F — Uneven
Brittle
When massive, radial fibrous, often mottled or banded. In fiasures and cavities in basic igneous rocks. With stilbite, analcite, prehnite, calcite.
C— -None FConchoidal, uneven
Brittle
— Prismatic, con- spicuous parting often noted
F — Cone hold a 1
Brittle
Compact masses often with red- dish, greenish, or whitish streaks and spots. In cracks and cavities in basic igneous rocks. With calcite, prehnite, epidote, native copper, zeolites.
With feldspars, pyroxenes, am- p h i b o 1 e s, chlorite, ecapolite.
F — Conchoidal,
Crystals commonly amall, highly modified; rounded grains in sand. With quarta, magnetite, zircon, garnet, thorite, gold, chromile, diamond.
Easily recognized by associates — nephelite, sodalite, biotite, feld- spar, titanite.
ijGoogle
B. HIHERALS WITH NOHrHETALLIC LUSTER
Streak — Uncolored, white, or Ught graj
Crystal!! nation Structure Crystals -C Massive M
♦HEPHELITE (Nepheline, Hexagonal
elffiolite) C — Short prismatic, (Na,K},Ali,0„ tabular
MoBea H — Compact, dissemi'
Kraus, Dana, Parsons Dated grains
232, 409. 395
Greasy Yellowish
Vitreous Reddish brown
Transparent to Brown opaque
Anthophyi-utb (Amphibole) (Mg, Fe),(SiO,).
Orthorhombic Vitreous Grayish brown
C — Prismatic, rare Pearly Yellowish
H — Lamellar, columnar, Translucent brown
fibrous Clove brown
Enstatite
Orthorhombic
Vitreous
Grayish brown
C— Prismatic, rare
Peariy
Greenish
Mg.(SiO,),
M— Fibrous, lamellar,
Translucent to
brown
columnar, compact
opaque
Yellowish
241. 3S4.
3S4
Brohzite
Orthorhombic
Bronsy
Bronze
C— Prismatic, rare
Silky
brown
(Mg,Fe),(SiO,),
M— Fibrous, lamellar.
Translucent to
Yellowish
compact
opaque
brown
242, 38S,
Hypersthene
Orthorhombic
Pearly
Dark brown
fS
C— Prismatic, tabular,
MetaUoidal
Blackish
g 1 (Fe,Mg),(SiO,)
'DIOPSroE
CaMg(SiO,)2
rare Translucent t
—Granular, foliated, opaque
cleavable aggregates
Monoclinic
C — Prismatic, thick
columnar, prism
angle sr H — Compact, granular,
columnar, lamellar
Vitreous Yellowish
Dull Brownish
Transparent to opaque
Rhodonite
Triclinic
Vitreous
Yellowish
C— Tabular', prismatic,
Dull
Brownish
MnSiO,
rounded edges M— Compact, cleavable, granular, dissemi-
Translucent to' opaque
248,
387 nated grams
ijGoogle
4. Yellow Or Brown Ih Color
Hnrdnesa 3 to G
Cleavage -C Fracture — F
Tenacity
C — IndiBtinct F — Conchoidal,
Diatinguished from orthoelase by inferior cleavage and more greasy luster. With feldspars, cancri- nite, biotite, Bodalite, corundum; not with quarti.
?hite C— Prismatic
Often with metallic achiller,
rayish F — Fibrous
resembling broniit* and hyper-
Brittle
sthene. Softer when altered. In crystalline schists. With talc, hornblende, mica.
white C— Prismatic,
pina-
Often softer due to alteration to
3,3
serpentine. Commonly in basic
Ous
igneous rocks. With olivine.
F — Uneven
chondrodite, serpentine, talc.
Brittle
/hite C— Priamfttic,
pina-
Cleavage surfaces usually fibrous
rayish coidal, conspicu-
or lamellar, irregular or wavy.
ous
with distinct broniy luster;
F— Uneven
darker than enatatite. In basic
Brittle
igneous rocks.
/hite C— Pinacoidal
con-
3,3
Copper red iridescence often noted,
rayish spicuous
3,5
due to smsU, tabular inclusions.
F— Uneven
In the more basic igneous rocks.
Brittle
With feldspar (labradorite), olivine, hornblende, pyrrhotite.
magnetite.
rhite C— Prismatic;
con-
ray spicuous basal
onal, with distinct basal parting.
parting
F— Uneven
monly with vesuvianite, garnet,
Brittie
fbiM C— Prismatic,
basal
Due to exposure may be stained
F— Conchoida even
un-
brown or black. FowlerUe, con- tains zinc. With franklinite,
Crystals brittle, tough
sincite, willemite, calcite, iron
when mass
ve
ores.
ijGoogle
B. HDTERALS WITH HOnOCETALUC LUSTER
Streak— Dncolored, white, or light gray
Crystalliiation Structure Crystals -C HasBive— M
Transparency
Willemite (Troostite)
Hexagonal
Greasy
Yellow
C— Prismatic
Vitreous
Greenish
H — Compact, granular.
Transparent to
yellow
Moaea
opaque
Brown
Krau., Dana.
Pa'-SoM
20e. 422.
OPAL, varieties
Amorphous
Vitreous
Yellow
Precious opal
H — Compact, reniform,
Greasy
Yellowish
SiO.xH.O Wood opal
botryoidal, porous.
DuU
brown
Opal jasper
earthy
Translucent to
Brown
SilM/ius HrUer
opaque
THpoliU
Orthite (Allaoite)
Monoctioic
Dark brown
C— Tabular, rare
Submetallic
Blackish
Ca,(Al,Cee>,(Al . OH) (SiO.).
H — Compact, granular,
Translucent to
brown
bladed, disseminated
opaque
Yellowish
201. 4M.
grains Tetragonal
brown
Anatase (Octahedrite)
Adamantine
Reddish bro
C— Pyramidal, tabular,
Metallic
YeUowish
TiO,
rarely prismatic
Translucent to
brown
7a. 348.
Orthorhombic
semi-opaque
Dark brown
Brookite
Adamantine
Dark brown
Only in crystals,— py-
Metallic
TiO,
ramidal (often with hexagonal habit).
Opaque
7fl, 347,
priEtnatic, tabular
Perovskite CaTiO.
*Amblygonite
Li(AlF)PO,
Pseudocubic Adamantine Pale yellow
CApparently cubes, Submetallic Orange yellon
highly modified, often Transparent to Reddish brown
striated translucent H — Reniform aggregates,
rounded grains
Triclinic Pearly Yellowish
C — Rare Vitreous Brawnish
M — Cleavable, columnar, Tranaluoent compact
:y
4. Yellow Or Brows Tb Color
Cleavage — C Fracture — F
Tenacity
Specific Gravity
—Basal, prismatic —Uneven
Crystals of willemite email, of
trooBtite, manganiferoua variety, often large. Characterized by aegociatea — franklinite, zincite, rhodonite, calcite.
F — Conchoidal, eon- epiouous when com- pact; earthy
Brittle
Precious opal, play of colore; wood opal, woody structure; opal jas- per, greasy, resembling jasper; silicioue sinter, porous; tripolite, earthy and gritty.
Gray
C— Pinacoidal, indis-
Often covered with brownish or
Greenish gray
tinct
yellowish alteration product. In
Brownish gray
F— Uneven, conchoidal Brittle
the more acid igneous rocks; also in limestone. With epidote, quartz, feldspar.
.6
White
C— Pyramidal, basal
3,8
Crystals often resemble elongated
Gray
F— Subconchoidal Brittle
octahedrons. With brookite, ru- tile, ilraenite, adularia, titan- itc, gold.
6.S Gray C — Indistinct
6. Yellowish white F — Uneven
Brownish white Brittle
Crystals may be striated; not twinned like rutile. With rutile, anatase, titanite, adularia, neph-
White Grayish
C — Cubical, indistinct F — Uneven Brittle
With chlorite, magnetite, lime- stone, serpentine.
pinacoidal, domatic F — Uneven Brittle
Usually in cleavable masses, showing excellent cleavage in one direction. Resembles orthoclase With lepidolite, rubellite, wavel- lite, petalite.
:y
B. Uherals Wtth Hoh-Hetallic Luster
Stresk
— Oncolored, white, or light gray
CrystalUzatioQ
Name, Composition, and
Structure
Luater
r 1
Refereacea
Cryatala -C Masdve-M
Transparency
*ORTHOCLASE (Feldspar)
Monoclinic
Vitreous
Pale yellow
C— Prismatic, thick tabu-
Pearly
Brownish
KA18i,0,
lar ; twins ; often large
Translucent to
yellow
M— Cleavable, granular,
opaque
Kraus. Dana, Pawom
disseminated
360. 370, 378
Chondrodile
Monoclinic
Vitreous
Reddish brown
C— Small, highly modi-
Greasy
Yellowish
[Mg(F,OH)),Mg,(SiO.),
fied, rare
Translucent to
brown
M — Rounded, dissemi-
opaque
Honey yello
nated grains, com-
197. 443. 409
pact
Zoisite
Orthorhombic
Vitreous
Brown
C— Prismatic, deeply stri-
Translucent to
Yellowish
Ca,Al,(A1.0H)(SiO.),
ated, bent, without
opaque
brown
good terminations
Yellow
— Columnar, broad
109. 437. 406
bladed, fibrous
SilUmanite (Fibrolite)
Orthorhombic
Vitreous
Hair brown
C — Long, thin, needle-
Silky
Grayish brown
like
Transparent to
M— FibrouB, columnar.
translucent
radiating
188, 433. 40E
Axinite
Triclinic
Vitreous
Clove brown
C— Broad tabular, with
Transparent to
Honey yellow
R,"R,"'B,(SiO.)5
sharp edges
Greenish
R"=Ca,Fe,Mn,Mg
M— Lamellar, granular
yellow
R"'-A],Fe
213. 441. 408
Epidote
Monoclinic
Vitreous
Greenish
C — Prismatic, elongated
Transparent to
brown
Ca,(AlJ-e),(AI.OH)(8iO.),
and deeply striated
opaque
Greenish
parallel to 6 axis;
yellow
usually terminated
YeUow
on one end only H — Columnar; fibrous, parallel and diver-
200. 438, 408
gent; granular
ijGoogle
4. Yellow Or Browv Dv Color
Hardness
yer 6
Hard-
neaa
Streak
Cleavage -C
Fracture -F Tenacity
Speciac Gravity
Characteristics and Associates
White
C — Basal, clinopina-
. —90= Brittle
Characterized by rectangular cleavages and absence of twinning striations. In granitic rocka. With quartz, other feldspars, mica, hornblende.
White
C— Basal, indistinct F— Conohoidal, uneven BritUe
Associates important. In crys-
With spinel, vesuvianite, pyrox- enes, mica.
White
C — Brachypinacoidal,
conspicuous F— Uneven
Brittle
Deeply furrowed and transversely broken columnar masses. In crystalline schists. With horn- blende, vesuvianite, quartz, epi- dote, garnet, feldspar.
White
C — Macropinacoidal F— Uneven Brittle
3,3 3,3
Crystals often slender, bent, stri- ated, with rounded edges, without good terminations, and interlaced. In metamorphic rocks— mica schist, gneiss. With andaluaite, garnet, iolite.
White
F— Conchoidal Brittle
3,3
Crystals, sharp wedge-shaped, glassy; frequently coated and intergrown with green chlorite. With quartz, adularia, albite, hornblende.
White
Grayish
C— Basal
F-Uneven
BritUe
3,3
3,5
Crystals often darker than when massive. With quartz, feldspar, vesuvianite, hornblende, pyrox-
snes, magnetite, prehnite, native sopper.
:y
MIHERALS WITH HOH-METALLIC LUSTER Streak— Uncolored, white, or light gray
Crystallisation Structure Crystals -C
Transparency
Diaspore AIO.OH
Ortborhombic
C — Broad columnar, tabular, rare
H — Scaly, confused I fibrous, bladed ag-
a gregates
Vitreous
Transparent to translucent
Rutile
TiOr TiTiO.
Tetragonal
Adamantine Reddish brown
C — Prismatic, vertically Submetallic Yellowish
striated; twinned. Translucent to brown
yielding knee-sbaped opaque Dark' brown
or rosette forms
M — Compact, dissemi-
♦GadoUnite
Monoclinic
C— Prismatic, rare
Vitreous Greasy
Brown
Fe[Be(Y,0)SiO,],
M— Compact, dissemi-
Translucent to
193,
nated
opaque
Cassitertte
Tetragonal
Adamantine
Reddish
C— Thick prismatic;
Greasy
brown
SnOi or SnSnO.
knee-shaped twins
Dull
Yellowish
quite common
Translucent to
brown
M— Renitorm, botry-
opaque
Dark brown
oidal, compact,
rounded pebbles.
often with internal
radial, fibrous struc-
4B tre, wood li,,
Ortborhombic
Vitreous
Reddish
C— Prismatic, rough,
Dull
brown
nearly square, often large, without termi- nations M— Columnar, fibrous, granular, dissemi-
Translucent to opaque
Brown
432, 404 nated
ijGoogle
4. Yellow Or Browr Ik Color
HardneBB over 6
Cleavage C Fracture -F
Tenacity
Specific ChBracteriHticB and
Gravity Associates
C Brae hypinacoidal ,
conspieuoua F— Conchoidal Brittle
Yellow and brown co
due to, limonite coating. With corundum, emery, dolomite, margarite, chlorite, magnetite.
Gray C — Prismatic, pyrami-
Yellowish white dal, not conspic-
Brownish white uous
F— Uneven
Brittle
Not as heavy as cassiterite. Often in fine hair-like inclusions. With quartz, feldspar, hematite, 'Imeii- ite, chlorite, brookite.
In granitic rocks and pegmatites. With fergusonite, orthite, fluor- ite, molybdenite.
White C— Indistinct
Yellowish white F— Uneven Brownish white Brittle
Distinguished by high specific gravity. In veins cutting gran- ite, gneiss; in alluvial de- posits as stream tin. With quartz, wolframite, scheelite, molybde- nite, tourmaline, fluorite.
C — Prismatic F — Uneven Brittle
Due to alteration, auri'ace may be covered with scales of mica, hence, softer. In metamorpbic
rocks often as rounded or knotty projections. With cyanite, silli- manite, garnet, tourmaline.
:y
B. Hiiierals Wtth Hoit-Hetallic Luster
Streak
— Dncolored, while, or gray
Name, Composition, and
Structure
Luster
Color
References
Crystals -C Massive -M
Transparency
Vesuviahite
Tetragonal
Vitreous
Brown
C— Short prismatic
Greasy
Greenish
CaJAl(OH,F)]Al,(SiO.),
H — Compsot, granular;
Translucent to
brown
Moses
aggregates with par-
opaque
Sulphur
allel or divergent
yellow
stria tions or furrows
♦Olivihe
Orthorhombic
Vitreous
Reddish
C— Prismatic, thick tabu-
Transparent to
brown
lar
YeUowiah
M— Rounded, disBcmi-
brown
nated grains; granu-
204. 420. 398
lar aggregates
GARBET, varieties
Cubic
Vitreous
Yellow
GroBBularile
C — Dodecahedrons, te-
Cinnamon
R,"R,"'(SiO), SpewarHte
tragonal trisoctahe-
opaque
brown
R"-Ca,Fe,Mg Almandile
droDs, alone- or in
Reddish
R"'-AI,Fe Aiidradiie
H — Granular, compact, lamellar, dissemi- nated grains, sand
brown
208, 41S. 3M
QUARTS Phanerocrystalline
Hexagonal
Vitreous
Yellow
varietieB
C— Prismatic, horizont-
Greasy
Yellowish
SiO, Smoky quarts
ally striated
Transparent to
brown
False topat
M — Compact, granular
opaque
Smoky broira
Aventurine Ferruginous ,
brown
CaVs eye
Cryptocrystalline
Hexagonal
Waxy
YeUow
varieties
C— Never in crystals
Vitreous
Brown
Chalcedony
M— Nodular, botryoidal.
Translucent to
Blackish
Agate
banded, concretion-
opaque
brown
Jasver
ary, stalactitic, com-
Flint
pact
70, 324, 372
.jGoogle
4. Yellow Or Brovh Ih Color
Hardness over 8
Cleavage — C
Fracture -F Tenacity
Characteristics and AsaociateB
C — Indistinct . F— Uneven
Brittle
In crystalline limestone, gneisa, schist. With garnet, tourmaline, chondrodite, wollastonite, epi- dote, pyroxenes.
White C— Pinacoidal
Yellowish white F — Conchoidal Brownish white Brittle
In basic igneous rocks — basalt, traps; crystalline limestone. With augite, magnetite, spinel, chromite, pyrope, plagioclase.
C— Dodecahedral, u
ally indistinct F — Conchoidal, unc
White C — Indistinct
Yellowish white F — Conchoidal, i Brownish white spicuous
Brittle
White C— Indistinct
Yellowish white F — Conchoidal, Browoish white spicuous
Brittle to tough
OrosguJaHte, in crystalline Ume- stone, dolomite, with wollastonite, vesuvianite, diopside, scapolite; speMartUe, in granitic rooks, with quartz, tourmaline, orthoclase; almandile, with mica, staurolite, andaludte, cyanite; andradiU, with epidote, feldspar, nepbelite, leucite.
Characteristic conchoidal fracture and glassy luster. Smoky quartz, smoky yellow to brownish black; false topaz, yellow; ouentwrine, glistening with included scales; ferruginous, colored by iron oxide, cals eye, opalescent, due to inclu- sions of fibers of asbestos.
Not as glaaay as phanerocrys- talline varieties. Chalcedony, pale to dark brown, waxy luster; agate, banded or clouded; jasper, commonly yellow and uniform in color; fiint, smoky or blackish brown, nodular, often with white coating.
:y
B. Buherals Wtth Hoh-Metallic Luster
Streftk — Uncolored, white, or light gray
Name, CompoBition. and fveiereaccB
CrystaUization Structure Crystals -C Massive
Luster Transparency
Color
QUARTZ, Clastic varietiee Sand S,0, Sandstone QuarUUe
and™ Kraue, Dana. Pftraom
Hexagonal '
H — Grains, fragments, either loose or strongly consoli- dated
Vitreous Dull
Translucent to opaque
Yellow Yellowish
brown Brown
70. 324. 372
Borwite
Pseudocubic
C— Tetrahedral, cubical,
small, well developed M— Compact, nodular,
fine fibrous
Vitreous Transparent to opaque
YeUow Grayish yeUow Brownish
Danburite
CftB.(SiO.).
Orthorhombic C— Prismatic, highly modified
Greasy
Tranepareut to translucent
Wine yellow Honey yellow Dark brown
Todrmalihe
M,'Al,(B.OH)i.O„ M'"Na,K,Li,Mg,Fe
183, 447. 409
Hexagonal
C— Prismatic, verticaUy
striated; terminated with broken or rhom- bohedral-like surfaces M— Compact, granular
Vitreous Translucent to
opaque
Brown Yellowish
brown Yellow
Staorolite
Fe{A!0),(AI.OH)(SiO.),
Orthorhombic
C — Prismatic; twins plua- (+) or X-shaped; well developed
Vitreous Dull
Translucent to opaque
Reddish
brown
YeUowish
Blackish brown
1S4, 450, 410
Phenacite
Hexagonal
ramidal, lenticular,
Vitreous translucent
Wine yellow Brown
205, 423. 3S9
ZIRCOH ZrSiO,
7B. 42, 402
Tetragonal
C— Square prisms and bipyramida, small, well developed
M— Irregular lumps, grains
Adamantine
Vitreous Greasy Transparent to
opaque
Reddish
brown Dark brown Brownish
yellow
ijGoogle
4. YELLOW OR BROWR m COLOR
Hkrdnesa over 6
Cleavage Fracture — F Tenacity
Characteristics and
White C— Indistinct
Yellowish white F — Uneven Brownish white Brittle to tough
Figment ia usually ferruginous matter. Sand, loose, unconsoli- dated grains; sandstone, con- solidated sand; quartzite, meta- morphosed sandstone.
White
C— None
2,9
Disseminated, glassy crystals com-
F— Conchoidal, uneven
mon; compact masses resemble
Brittle
fine grained marble. With gypsum, anhydrite, halite, car- nallite.
White
C— Indistinct
2,9
Resembles topaz, but cleavage
7.B
Brittle
not as perfect. With calcite, dolomite, mica, microcline, py- roxene, tourmaline.
White
C— None
Spherical, triangular cross-section.
F— Conchoidal, uneven Brittle
Commonly as contact mineral in granular limestone and dolomite. With tremolite, scapolite, vesu-
vianite, apatite, garnet, spinel.
White
C— Brachypinacoidal
3,4
Fresh crystals usually possess
F— Conchoidal, uneven BritUe
bright, smooth faces, when al- tered dull, rough, softer and with colored streak. In metamorphic
With cyanite, garnet, tourmaline,
White
C— Indistinct
3,
Distinguished from quartz and
F— Conchoidal Brittle
topaz by crystal form and cleavage. In pegmatites and metamorphic rocks. With quartz, topaz, beryl, amaionstone, chrysoberyl.
White
C— Indistinct
4,4
In the more acid igneous rocks —
F — Uneven
4,8
granite, syenite; alluvial deposits,
Brittle
net. Hyacinth, clear and trans-
parent.
ijGoogle
B. MIHERALS WITH IfOH-HETALLIC LUSTER
StreakUncolorad, white, or liEhl gnj
CrystaUiaatioD Structure Crystals -C Massive— H
Transparency
257,
40S.
Hexagonal
C— Iiong prismatic, often vertically striated, HoBH large
Pona f — Colutunar, granular, 391 compact
Vitreous Pale yellow
Tranapareut to Honey yelloi
translucent Brownish
SPIHEL, varieties
Pleonasle R"(R"'OJ, GakniU
R"-Mg,re, Zn
R'" -A!,Fe
157. 338. 341
Topaz
Al,(F,OH),SiO.
C — Octahedral, well de- veloped
H — Compact, granular, disseminated grains
Ortho rhombic
C — Prismatic, vertically
striated, highly
modified H — Compact, granular,
rolled fragments
Vitreous Yellow
DuU Grayish
Nearly opaque brown Brown
Vitreous Straw yellow
Transparent to Wine yellow opaque Yellowish
brown
ISl. 342, 3K
COROHDmi, varieties
Oriental
A1,0, U)pa2
Common
Orthorhorabic Vitreous Yellow
CTabular; heart- Greasy Greenish
shaped, pseudohex- Transparent to yellow
agonal twins translucent Brown
M — Fragments, loose, rounded grains
Hexagonal Vitreous Yellow
C — Prismatic, tabular, Translucent to Brown
pyramidal, rhombo- transparent
hedral; rough or
rounded barrel-
:y
4. Yellow Or Brown Ih Color
Hudnesa over 6
Cleavage -C Fracture -F
Tenacity
C — Basal, indistinct F— Conch Old a 1, uneven Brittle
Crsrstala usuaUy simple, prism and base. In granitic rocks, mica schists, clay slates. With quarti, feldspar, mica, chrysoberyl, topaz, caseiterite, garnet.
C — Indistinct F — Conchoidal BritUe
Commonly as contact mineral in granular limestone; in more basic igneous rocks- as rounded grains in placers. With calcite, cbon- drodite, serpentine, bnicite, graphite, pyroxenes.
C — Basal, perfect, ci
spicuous F — Conchoidal, une Brittle
Crystals usually developed on one end only. Color may fade on exposure. Massive varieties dis- tinguished from quarti by higher specific gravity and basal cleavage. In veins and cavities in granitic rocks, also in placers. With cassiterite, tourmaUne, fluor- ite, apatite, beryl, wolframite.
C — Brachypinacoidal 3 , 5 Crystals disseminated as plates,
FUneven, conchoidal 3,8 often with feather-like or radial
Brittle striations. In granite, gneiss,
placers. With beryl, garnet,
tourmaline, sillimanite.
CNone, nearly rec- tangular basal and rhombohedral part- ings, conspicuous; often striated
F — Conchoidal
Brittle to tough
When massive often multicolored — red, blue, green, gray. Orien- tal topai, transparent, yellow. In limestone, granite, syenite. alluvial deposits. With magne- tite, nephelite, mica, spinel, chlorite.
:y
B. Minerals With Voh-Hetallic Luster
Streak
— Dncolored, white, or Ut gray
Crystallization
Structure
Luster
Color
References
CryatalH-C Massive -M
Transparency
Ulexite
Silky
White
C— Aoicular, capillary
Pearly
Snow white
NaCaB.6,,6H,0
M— Fine fibrous inter- woven, ball-like ag-
Translucent
Kraus, Dana
p™ns gregates
163. 520,
Vatron (Soda)
Monoclinic
Vitreous
Colorless
M— Crystalline crusts,
Earthy
Gray
Na,CO, 10H,0
earthy effioreecences
Transparent to translucent
Yellowish white
126. 366,
Cerorgyrite (Horn silver)
Cubic
Waxy
Pearl gray
Greasy
Grayish
AgCl
M— Wax-like crusts, coatings; stalactitic, dendritic
Transparent to translucent
101. 319.
Catuallite
Orthorhombic
Vitreous
Milk white
C— Pseudohexagonal,
Dull
Gray
MgCI, KCI.6H,0
rare
Transparent to
Colorless
108. 323.
H — Compact, granular
translucent
Calomel
Tetragonal
Adamantine
White
C— Small, tabular py-
Translucent
Grayish '
Hg,Cl,
ramidal
to nearly
Yellowish
105, 317.
M— Coatings Orthorhombic ?
opaque
white
Asbestos, variety
Silky
White
Chrymlile
H — Coarse or fine fibrous,
Silky raetalUe
Greenish
H.Mg,Si,0.
felted
Opaque
white Yellowish
226, 478.
white
variety
Silky
White
Amph'a>ole
M-Coarse or fine fibrous.
Dull
Greenish
Silicate of Ca, Mg, Fe, Al, etc.
felted; compact.
Opaque
white
leather- or cork-like
Yellowish
253, 401,
Dull
white
TRXPOLITE (Opal)
Amorphous
Gray
M— Porous, earthy, chalk-
Opaque
White
SiO,.xH,0
like
Yellowish
88, 329,
white
ijGoogle
S. COLORLESS, WHITE, OR LIGHT GRAY m COLOR
Tasteless. Soft, fibrous, rounded with loose texture, ap- parently very light. Easily pul- verised between fingers. With halite, gypsum, glauberite, borax.
1. White, shiny 1.6 Gray, shiny
C— None
F — CoDchoidal
Highly sctile
C — Indistinct F — Conchoidal
Brittle
1.4 Natural crystals unknown. Taste
1. 5 alkaline. Loses water on expo- sure to air. Principally in soda lakes. With halite, trona, ther- monatrite.
5.5 Cuts like wax, yielding shiny sur-
5.6 faces', on exposure turns violet, brown, or black. With silver minerals, especially argentite, native silver; also Umonite, cal-
1 . 6 Bitter taste; absorbs moisture. With halite, kieserite, sylvite, anhydrite, boracite.
1. White
2. Gray
C — Indistinct F— Conchoidal
Very aectile
P— Fibrous Flexible
F— Fibrous Flexible, tough
Characterized by high specific gravity and associates, especially cinnabar, native mercury; also barite, tetrahedrite.
Short fiber ed (wdeatos, delicate, fine, parallel, flexible fibers, easily separable. Compare below. In veins or seams in compact ser-
Long fibered asbeatos, parallel, flexible fibers. Compare above. Mounlain teatker, mountain cork, mountain wood, compact, but light and tough.
Apparently very soft, but fine par- ticles scratch glass. Resembles chalk and kaolinite, but gritty, and not plastic when moistened.
:y
B. Muterals With Non-Metallic Luster
Streak— Dncolored, white, or IJglit gra.7
Name, Composition References
CrystaUiiatioQ Structure Ctyrtala-C Uassive— H
Transparency
KAOLnnTE( Kaolin, china clay) Honoclinic
C— Scaly, rare H.AJjSiiO, M— Compact, friable,
mealy, clay-like
Mvaee
Dull White
Peariy Gray
Opaque to Colorless
translucent
330,
4S1.
CALCITE, varieties
Hexagonal
Earthy
White
Chalk
M — Loose or compact.
Dull
Grayish
CaCO, Marl
earthy
Opaque
YeUowish
Iii. 354,
white
TALC, varieties
Monoclinic
Pearly
White
C— Thin tabular, indis-
Greasy
Greeni whiif
H,Mgi.O„ or steam
tinct
Transparent to
Gray
French chalk
M— Foliated, globular, fibrous, granular, compact
opaque
227. 470,
Pyrophyllite
Pearly
White
C— Indistinct
Greasy
Greenish while
H,Al,Si.O„
H — Radiated, fibrous, lamellar aggregates;
Dull Translucent to
Gray
231. 482,
opaque
Bauxite
Never in crystals
Dull
White
H — Pisolitic, ooUtic,
Earthy
Grayish
- A1,0(0H).
rounded disaemi- Dated grains; clay-
Opaque
B4, 350.
like, earthy
MirabiUte {Glauber salt)
Monoclinic
Vitreous
Colorless
C— Rare
Transparent to
White
NaO..10H,O
M— Mealy efHorescenees,
opaque
YeUowish
149. S31,
fibrous crusts
(diite
Sal Ammoniac
Cubic
Vitreous
Colorless
C— Distorted, rare
Transparent to
White
NH.Cl
M— Fibrous, powdery,
translucent
Grayish
99. 31.
3Is
stalactitic, crusts
.jGoogle
6. COLORLESS, WHITE, OR LlCm' GRAY IH COLOR
Cleavage —C Fracture — F Tenacity
Characteristics and Aaeociatea
1. White
C— Basal (scales)
F— Earthy
BritUe
Not gritty like tripolite. Very strong clay odor when breathed upon . Usually adheres to tongue and becomes plastic when mois- tened. Greasy feel. With quartz, feldspar, corundum, dia-
White
C— None
Chalk, earthy masses; marl, more
F— Earthy Brittle
clay-like and frequently contains organic material— leaves, twigs.
In extensive deposits.
C — Basal, conspicuous,
when foliated F — Uneven, splintery Sectile, lawinie Bexible
C— Longitudinal F — Fibrous, uneve: LanunEe flexible
Greasy or Boapy feel important. Foliated talc, easily separable, inelastic folia or plates, H— 1; goapalone or aUaiiie, coarse to fine granular, rather impure, H — 1.5—2.5; Frerich chalk, soft, compact, marks cloth distinctly. With serpentine, dolomite, chlorite, magnesite, actinolite.
Soft and greasy like talc, but usually in radiating fibers. In schistose rocks. With cyanite, lazulite, graphite.
C — Orthopinacoidal F — Concfaoidal Brittle
C — Indistinct F— Conchoidal Brittle
Clay odor when breathed upon. Usually distinguished from clay by pisolitic or oolitic structure. With clay or kaolin in nodules, grains, or irregular masses in limestone or dolomite.
Taste, cool, then slightly salty and bitter. On exposure loses water, turns white, and crumbles. With halite, Kypsum, clay, marl.
Pungent, salty taste, somewhat astringent. Usually sublimation product. Near volcanoes, burn- ing coal beds, guano deposits.
cyGoogIc
B. Hdierals With Hoh-Metallic Luster
Streak — Dncolored, white, or light gray
CrystallizatioD Structure Crystals -C Massive— H
Transparency
Struvite
NH,MgP0,.6H,0
Orthorhombic C — Domatic, hemi- morphio I M — Granular, earthy
Vitreous Gray
DuU White
Translucent to Colorless opaque
Niter (Saltpeter) KNO,
110, 517, 311
SODA UTTER (Chile saltpeter) NaNO,
lOe, 517, . 314
Orthorhombic
C — Pseudohexagonal,
H — Crusts, fine needle- like aggregateB; efflo-
Vitreous Colorless
Translucent White
Gray
Hesagonat
C — Similar to those of cal-
H — GranulBr,cruBts, efflo-
Vitreoua Colorless
Tranaparent White
Grayish
GYPSUM, varieties
SeleniU CaS0,.2H,0 Satin epor
Common
146, 631,
Honoclinic
C — Tabular, prismatic; swallow-tail twins
H — Cleavable, coarse or fine grained, fibrous, foliated, earthy
Pearly Colorless
Vitreous White
SiHty Gray
DuU Transparent to
Vlviamte Fe.(P0.),.8H,0
178, 508,
Monoclinic
C — Prismatic, tabular H — Reniform, globular, with radial fibrous
structure; earthy
Vitreous Colorless
Dull Bluish white
Transparent to Greenish wltite opaque
Copiapite (Misy)
Monoclinic
Pearly
White
C— Tabular, six-sided
Dull
Yellowish
Fe,(Fe,OH),(80.)(.18H,0
M— Granular, scales, pow-
Translucent
white
152, 636, 22
der
Helanterite (Copperas) FeS0,.7H,0
Isi, 634, 223
Monoclinic C— Rare
M — Capillary, fibrous, stalactitic, concre- tionary, powder
Vitreous White
Dull Greenish white
Transparent to Yellowish
translucent white
:y
6. Colokless, White, Or Light Gray In Color
Hudaen 1 to 3
Hard- ness
Streak
Cleavage -C Fracture -F Tenacity
Specific Gravity
Characteristics and
Associates
White
F— Conchoidal Brittle
nounced hemimorphism. In sewers, vaults, guano deposits.
White
C— Indietinct F— Conchoidal Brittle
2,1
Cooling and saline taste. Does not absorb moisture. As an efflorescence; in limestone caves. Never in extensive deposits like soda niter.
White
C— Rhombohedral
F-Conchoidal
Brittle
Coolingand saline taste. Absorbs moisture readily. In extensive deposits. With gypsum, sand, clay, guano.
White
C— Clinopinacoid al,
ramidal, orthopina-
coidal F— Conchoidal, fibrous Brittle, lamime flexible
Selenite, crystals and cleavage plates, usually transparent; satin epar, fibrous with silky luster;
stones, shales. With halite, celestite, sulphur, aragonite, ore
deposits.
White Bluish white
C— Clinopinacoidal F— Fibrous, earthy Sectile, thin lamioie flexible
2,7
Usually massive. On exposure color and streak change rapidly to blue. Id clay, peat, bones, sheUs. With limonite, pyrrho- tite, pyrite.
White YeUowiah white
C— Pinacoidal
F— Earthy, scaly Brittle
2,1
Disagreeable metallic taste. Oxi- dation product of iron sulphide
pyrrhotite.
White
C— Basal
F — Conchoidal, earthy
Brittle
On exposure loses water and crumbles. Sweet, astringent taste, somewhat metallic. Oxi- dation product of iron sulphide
chalcopyriite, pyrrhotite.
ijGoogle
B. Uherals With Hoh-Hetallic Ldster
StreBk — Uncolored, white, or light gny
Cryatallusatioa Structure Crystals -C Massive— H
TranapareDcy
SeoUte (Meerachaum) Monoclinic ? Dull
M — Compact, uodular Opaque
H,Mg,Si,Oi, with smooth feel;
Moses earthy, cfay-like
Knua, Dnna, Famoiu
White Grayish white
Borax (Tinkal) Na,B.O,.10H,O
EfMomite (Epsom salt) MgS0,.7H,0
Modoc tinie
C — Short columnar
M — Compact, earthy
Orthorhombic
C — Prismatic, nearly
square, rare M — Granular, fibrous,
earthy, crusts
Vitreous Colorless
Greasy WhiU
Dull Grayish Translucent to opaque
Vitreoiia White
Dull Colorless
Transparent to Gray translucent
Sylrite
Cubic
Vitreous
Colorless
C— Cubes, alone or with
Transparent to
White
KCl
Bs, 31B,
310 M — Compact, granular
Grayish
HALITE (Rock salt) NaCl
Bmcite MgCOH),
C— Cubes, often skeletal or hopper-shaped
M — Compact, cleavable, granular, fibrous, stalactitic, crusts
Hexagonal
C — Broad tabular
MFoUated, scaly,
Vitreous Colorless
Transparent to White translucent Grayish
Pearly Colorless
Vitreous White
Transparent to Greenish translucent white
Monoclinic Vitreous White
C— Rare Pearly Grayish
H— Fibrous, botryoidal. Translucent to crusts, powder opaque
:y
6/ COLORLESS, WHITE, OR LIGST GRAY m COLOR Hardness 1 to 3
Hard-
Streak
Cleavage -C
Specific
Characteristics and
""
Tenacity
White
C— None
Recognized by smooth feel, ad-
F— Conchoidol, uneven Brittle
hereoce to tongue, low specific gravity and lack of clay odor when breathed upon. Impressed by finger nail. With serpentine, magnesite, chlorite.
White
C — Indistinct
Usually coated with white pow-
F— Conchoidal Brittle
dery crust. Feebly alkaline taste. In muds of alkaline lakes. With halite, natron.
White
C — Brachypinaooidal
Non-hygroscopic. Bitter, salty
P— Conchoidal Brittle
taste. In limestone caves.
With serpentine, talc, magnesite.
White
C— Cubic
Salty bitter taste. May absorb
F— Conchoidal
Brittle
moisture and become damp. In salt deposits. With halite, kai- nite, caroallite.
White
C — Cubic, perfect, con-
May absorb moisture and become
F— Conchoidal Brittle
damp. Characteristic cubical cleavage and sahne taste. With alate, gypsum, anhydrite, poly- halite.
White
C— Basal, perfect, con-
Thin plates or scales flexible
sum) by more pearly luster, slightly greater hardness, and crystal from; from muscovite by non-elasticity of plates or scales; foliated talc is softer with greasy
White
C— Clinopinacoidal,
May be reddish or greenish due to
rarely observed P — Uneven Sectile. thin lamine
flexible
admixture of erythrite or anna- bergite. Commonly as powder or stain on arsenic minerals.
ijGoogle
216 B. Mdierals With Voh-Hetaluc Luster '
Streftk— Uncolored, wUte, or light gny
CrystalliMtion
Name, CompOBition, and
Structure
Luster
oor
Crystals -C
Transparency
Massive -M
Cubic
Greasy
Colorless
C— Octahedral
Peariy
White
Sb.O.
M— Granular, crusts
Transparent to
Gray
Kniu. Dana, Pbiwuu
translucent
Sb. 330. 275
LepidoUte
Peariy
"Vhite
1 (Li,H),(F.OH),AIi,0.
C~Short prismatic
Translucent
Pinkish white
H — Coarse or fine granu-
Lavender
lar, scales, cleav-
Gray
able plates
1 219, 7, 317
Paraoonitb
Honoclinic
Peariy
Grayish
H— Compact, fine scaly
Translucent
Yellowish
. H,NaAl.(8iO.).
aggregates
white
.
Greenish
g 218. 487.
wbite
, MUSCOVITE (lainglass)
Moocwlinic
Vitreous
Colorless
C— Tabular, pyramidal,
Peariy
YeUowish
H,KAl,CSiO.),
with ortfaorhombic
Transparent to
white
or hexagonal out-
translucent
Brownish
line; often large and
white
rough
H— Scales, plates; foli-
ated and plumose
217. 4M. 417
aggregates.
APATITE, variety
Hexagonal
DuU
White
Phoaphaie rock
M— Compact, fibrous,
Opaque
Gray
Ca5F(P0.)„ chiefly
nodular, reniform,
170, 497, 330
earthy
Grubnbritb (Amphibole)
Monoclinic
Silky
Gray
C— Fine acicular
Translucent to
Greenish gray
FeSiO,
M— Fibrous, lamellar
opaque
353, 401,
Glauberite
Vitreous
Colorless
C— Thick tabular
Greasy
White
M — Reniform, lamellar
Transparent to
Gray
132, S23, 314
.jGoogIc
6. Colorless, White, Or Ught Gray Ik Color
Hardness 1 to 3
Cleavage — C Fracture -F Tenacity
Cliantcteristics and
ABBociates
White
C— Octahedral, indis-
Pearl colored octahedrons. With
tinct F— Uneven Brittle
ores of antimony — stibnite, ker- mesite, native antimony
White
C— Basal, perfect
F— Scaly granular Tough
2,9
granular limestone. In pegma- tites, granites, gneisses. With red tourmaline (rubellite), am-
ite.
White
C— Basal, perfect
Distinguished from other micas
F— Scaly, granular Tough
2,9
lite, tourmaline.
White
C— Baaal, perfect, con-
2,8
Structure, perfect cleavage, and
Tough, lamirae very elastic
elasticity important. Large crys- tals often show distinct part- ings perpendicular to cleavage, Ttded miea. In granitic rocks, schists, limestones. With feld- spar, quarts, beryl, tourmaline.
garnet, spodumene.
Whit*
F— Conohoidal, uneven
3,1
More or less impure masses, (re-
Brittle
quently resembling compact Ume- stone. Independent beds, nod-
ules, concretions.
CFibrouB Brittle
Usually with quarts, magnetite, and known as magnetite-grtiTteriU
C— Basal
F — Conehoidal
Brittle
Bitter saline taste. On exposure becomes coated with white pow- dery crust. With halite, the- nardite, mirabilite.
zjcCyGoOgIC
B. mutkrals with voh-bietallic luster
streak — Uncolored, wblte, or Vt er&y
Crystallizatioc Structure Cryatals -C Massive— M
TreDsparency
LeadtuUite PbS0,.2PbC0,.Pb(0H),
Knua, Dan
145,
Kainite
MgS0j.KC1.3H,0
Honoclinic Pearly White
CTabular, paeudohex- Adamantine Gray
agonal; twins, tril- Transparent to Colorleea lings translucent
a M — Compact, lamellar
MoDoclinic
C — Tabular, prismatic.
H — Compact, fine
VitreouB Colorless
Transparent to White
translucent 'Gray
Trona
Monoctinic
Vitreous
Colorlesa
C— Tabular, acicular.
Pearly
Gray
Na,C0,.NaHC0,.2H,0
colunmar
Translucent
Yellowiah
127, 367,
315 M— Crusts
white
Glbbaite (Hydrargillite). AltOH),
MoQoclinic
C — Tabular, pseud ohes- agonal, rare
M— Stalactitic, mam- millary, surface smooth, internal structure, fibrous; scaly aregatea
Pearly White
Vitreous Grayish
Translucent
CRTOLITE Air,.3NaP
107. 321. 346
BARITE (Heavy spar) BaSO,
136, 524. 319
Kieserite MgSO.H.O
Monocliuic
C — Small, pseudocubical
M— Cleavable, compact,
granular Orthorhombic C — Tabular, prismatic;
crested divergent
groups M— Compact, cleavable,
lamellar, fibrous,
Monoclinic Vitreous Colorlesi
C — Pyramidal, rare Transparent to White
M — Compact, granular translucent Gray
Vitreous Snow white
Greasy Gray
Pearly Colorlesa Transparent to
translucent
Vitreous Colorless
Pearly White
Transparent to Gray
translucent
6. Colorless, White Or Light Gray In Color
Hardness 1 to 3
Hard-
Streak
Cleavage -C Fracture
Tenacity
Specific Gravity
CharHCteristics and Associates
White
C— Basal, perfect F— Conchoidal, rarely
observed Rather Bectile
Soft and very heavy. Twins and trillings resemble those of arago- nite. With lead minerals, but sparingly. Fseudomorphous after calcite, galena.
White
made, not conspic-
F— Uneven Brittle
Taste, salty, bitter and astringent. Non-hygroscopic. With halite, sylvite.
White
C— Pinacoidal
F-Uneven
Brittle
2,2
Taste alkaline. Does not alter on exposure. As an efflorescence; in soda lakes. With halite,
glauberite, mirabilite, hanksite.
White
C— Basal, not con-
Bpicuoua Tough
Strong clay odor when breathed upon. With bauxite, natrolite, limonite, corundum.
C— Basal, prismatic, nearly at 90°; some- times conspicuous
F — Uneven
Brittle
Basal, prismatic, conspicuous
F — Uneven
Brittle
Frequently resembles snow ice. Often contains disseminated siderite, chalcopyrite, galena, pyrite, fluorite, columbite.
Characterized by rather high spe- cific gravity and cleavages. In metalliferous veins; pockets and lenticular masses in limestones. With galena, sphalerite, fluorite, chalcopyrite; manganese and
C— Pyramidal F-:— Granular Friable to firm
Due to absorption of water, be- comes coated with white crust of epsomite. With halite and po- tassium salts — carnallite, kainite, sylvite.
.7 o Ogle
B. HUfERALS WITH VOIT-METALLIC LUSTER
StTMk-IJocolored, wUte, or gray
CrystalliEstion
Name
Composition, and
Structure
Luster
References
CrystttU-C Massive -H
Transparency
Calcite,
varieties
Hexagonal
Vitreous
White
Dog tooth ipar
Dull
Grayish
CaCO,
NaU head ipar
bohedral, prismatic,
Transparent to
Colorless
Iceland spar
tabular, acicular;
nearly opaque
Satin spar
highly modified;
Limestone
twins
Coquina
H— Cleavable, granular,
MarbU
ebrous, banded, stal-
Travertins
actitic, oolitic, por-
Stagmilei
ous, compact, cruets.
Tkinotite Moa
shells
Knua. DuiB, Paraani
111, 3M, 333
Wulfenite
Tetragonal
Adamantine
Gray
C— Square, thin tabular;
Resinous
Yellowish
PbMoO,
more rarely pyrami-
Transparent to
gray
dal
translucent
Greemsh gray
H— Coarse, fine grained
139, Ml, 305
Streak — Ducolored, white, or lift gray
Gibbsite (Hydra rgillite) AI{OH),
Monoclinio Pearly White
C — Tabular, pseudohex- Vitreous Grayish
agonal, rare Translucent
H — Stalactitic, mammil-
351, 3S0
fibrous; scaly aggre-
Polalite
K,MgCa,(S0,),.2H,0 153, 535,
Uacommon color.
Monoclinic ? Greasy White
C — Indistinct Pearly Reddish white
M — Compact, fibrous, Translucent Gray lamellar
:y
6. COLORLESS, WBITE, OR LIGHT GRAY m COLOR
Hardness 1 to 3
Cleavage — C Fracture — F Tenacity
C— Rhom bohedra) , perfect, usually conspicuouB
F — Conchoidal
Brittle
Rhombohedral cleavage charac- teristic, especially on crystals. Cleavage surfaces often striated. Very strong double refraction easily observed when transparent. To distiDguiah varieties, see ref*
C— Indistinct P— Conchoidal,
Square plates, sometimes with forms of third order. With lead minerals — galena, pyromorpbite, vanadinite.
Strong clay odor when breathed upon. With bauxite, natrolite, limonite, corundum.
Taste, bitter and astringent, but weak. With halite, anhydrite, gypsum, clay.
JyGoOgIc
B. Huierals Wiib Ron-Hetallic Luster
Streak — Uncolored, white, or Ugbt gray
CrystallisatioD Structure Crystab-C MaBBivc ""U
Luster Trstuparencf
Ahhydrite
Orthorfaombic Vitreous White
C— Thick tabular, pria- Pearly Bluish white
matic, rare Transparent to Reddish white
MoB H — Granular, compact, translucent Grayish PusDTia fibrous, cleavable, 327 lamellar, jeniform
Celestite
SrSO.
Orthorhombic Vitreous Colorless
C — Tabular, prismatic, Peariy White
common; pyramidal Transparent to Gray M — Compact, cleavable translucent
fibrous, granular,
reniform
BARITE (Heavy spar)
Orthorhombic
C — Tabular, prismatic;
crested divergent
groups H— Compact, cleavable,
lamellar, fibrous,
reniform
Vitreous Pearly White
Transparent to Gray translucent
Orthorhombic Adamantine Colorless
C — Prismatic, tabular, Greasy White
pyramidal Transparent to Gray
H — Compact, granular, translucent
odular
Orthorhombic
C — Tabular, prismatic, pyramidal; pseudo- hexagonal; clusters and star-shaped groups
H — Interlaced bundles, granular, atalactitic, compact
Adamantine Colorless Greasy Whit*
Silky Gray
Transparent to translucent
cyGoole
White, Or Light Gray In Color
HaidaeBS 3 to 6
Cleavage - Fracture —
Tenacity
C— Pinacoidal, 3 direc-
times conspicuous F — Conchoidal Brittle
Pseudocubical cleavage sometimes noted. Granular varieties resem- ble marble or tumps of sugar. Not aa heavy as celestite or ba- rite. In limestones, shales. With halite, gypsum.
C — Basal, prismatic
conspicuous F — Uneven Brittle
Usually with faint bluish tinge. Heavier than calcite, anhydrite; lighter than barite. Good cleav- ages. In limestones, dolomites, shales. With sulphur, gypsum, aragonite, halite, galena, sphal-
C — Basal, prismatic,
conspicuous F— Uneven Brittle
Characterized by rather high spe- cific gravity and cleavages. In metalliferous veins; pockets and lenticular masses in lime- stones. With galena, sphalerite, fluorite, chalcopyrite; manganese and iron ores.
C — Basal, prismatic P— Uonchoidal Brittle
Luster and very high specific gravity important. Distin- guished from ceruBsite by absence of twins. Oxidation product of lead minerals. Usually in cracks and cavities, with galena, cerus-
C — Indistinct F — Conchoidal Brittle
Twinning, structure, luster, and specific gravity characteristic. With lead minerals— galena, pyromorphite, anglesite; also malachite, limonite.
:y
Boherals With Hoh-Hetallic Luster
Streak— Uncolored, white, or light gray
Name, Compoaition, and
CrystBlliiation Structure CryatalB-C Massive -M
j Traosparency
niLBITE (DeBmiae) Monoclinic Vitreous Wtiit
C — Twinned, sheaf-Uke, Pearly Yellowish
(Ca,NaJAli.0„.6H,0 radial, or globular Transparent to white
Moa aggregates translucent Gray
Kraus. Duu, PftTMD*
45a.
S Heulanditc
H.CaAl,{SiO.),.3H,0
2Si,
454,
Monoclinic Vitreous White
C— Tabular, striated Pearly Gray
M — Foliated, granular, Transparent to globular translucent
Lkumontlte Monoclinic
C — Columnar Ca{A1.20H),(8i,0,),.- M— Radial, divergent,
2H,0 earthy
286, 457.
LepidoUte (Mica)
(Li,H),(P,OH)li,0,
21 a. 467,
Hoigarite H,CaAl.Si,0„
221. 470,
Phosphate rock (Apatite)
CaJ(PO,)„ chiefly
170, 497,
Ahdalustte
Vitreous White
Dull Reddish
Transparent to white
opaque Gray
Monoclinic Pearly White
C-Short prismatic Translucent Pinkish white
H — Granular, coarse or Lavender
fine; scales, cleavable Gray
Monoclinic Pearly Pearl gray
C — Six-sided scales, Vitreous White
plates Translucent Reddish while
M — Scaly, platy, foliated,
granular
Hexagonal Dull White
H — Compact, fibrous, Opaque Gray
nodular, reniform,
earthy
Orthorhombic Vitreous White
C — Prismatic, rough, Dull Pearl gray
nearly square, often Transparent to Reddish gray
laige without termi- opaque
nations M — Columnar, fibrous,
granular, dissemi-
:y
5. Coloriss. White Or Light Gray Ht Color
HardnesB 3 to 6
Cleavage — C Fracture -F Tenacity
C — Pinacoidal F — Uneven Brittle
Radial or sheaf-like Ht,ucture. basic igneous rocks; ore deposits With chabasite, apophjUite, heu- landite, datolite, calclte.
In
White
C— Clinopinacoidal
perfect F— Uneven Brittle
White
C — Clinopinacoidal,
prismatic F — Uneven, eart,hy Brittle, friable
White
C— Basal, perfect F — Scaly, granular Tough
White White
C— Basal, perfect, con-
F — Scaly, granular Tough
F— Conchoidal, uneven Brittle
White
C— Prismatic F— Uneven Brittle
In basic igneous rocks; metal- liferous veins. With chabante,
stilbite, apophyllite, datolite.
On exposure becomes dull and crumbles to powder. In cavities and fissures in basic igneous rocks. With stilbite, apophyl- lite, analcite, native copper.
When massive often resembles granular limestone. In peg- matites, granites, gneisses. With red tourmaline (rubellite), amblygonite, spodumene, topaz.
Resembles the micas in structure and cleavage, but harder, lamiiue brittle and inelastic. With chlorite, corundum, emery, dia-
More or less impure masses, fre- quently resembling eompact lime- stone. Independent beds, nod- ules, concretions.
Due to alteration, surface may be covered with scales of mica, hence, soft. ChiastoliU, regular, internal arrangement of dark, organic matter, best seen in cross-section. In metamorphic rocks, often as rounded or knotty projections. With cyanite, sil- limanite, garnet, tourmaline.
:y
B. Hiherals With Nor-Hetallic Luster
Streak
— Oncolored, white, or light gray
Crystalliiation
Name, CompoHit
on, and
Structure
Luster
Color
References
CryBtalB-C
Transparency
Massive -M
WayelHte
Orthorhombic
Vitreous
White
C— CapUlary, small
Translucent
Gray
(Ai.Oh),{Po.), 5H,0
M— Cruata, globular or
ColorieBS
hemispherical, with
Kraia,
Dua
and
radial fibrous struc-
S12.
ture
Alunite (Alum stone)
Hexagonal
Vitreous"
C— Rhombohedrons, re-
Peariy
White
K,(A1.20H).(80.)
sembling cubes; tabular, rare H — Compact, granular.
Transparent to translucent
Gray
143,
537,
fibrous, earthy
Dolohite
Hexagonal
Vitreous
"White
C— Rhombohedral with
Peariy
Gray
CaMg{CO,),
curved surfaces (pearl apar) M— Coarsely crystalUne, compact, granular,
Transparent to
translucent
Coloriess
357,
33
triable
AHAGOHrre
Orthorhombic
Vitreous
Colorless
Greasy
White
CaCO.
prisms; radial, colum- nar, acicular aggregates M— Branching forms (s/em"),Htalactitic, reniform, crusts,
Transparent to translucent
Gray
lis,
3S1.
oolitic
stROHTIAHITE
Vitreous"
Colorless
C — Spear-shaped, colum-
Transparent to
Gray
SrCO,
nar, aciciilar, often divergent M— Granular, compact,
translucent
White
362,
fibrous, botryoidal
Sidehite
Hexagonal
Vitreous
Gray
C— Rhombohedral,
Pearly
Brownish graj
FeCO,
curved or saddle- shaped M— Cleavable, granular,
Yellowish graj
lis.
359,
compact, botryoidal
.jGoogle
COLORLESS, WHITE, OR LIGHT GRAY HI COLOR H&rdness 3 to 6
Cleavage -C Fracture — F
Tenacity
C — Pinacoidal, domat-
F — Uneven, conchoid-
al Brittle
Secondary mineral, oeeurring on surfaces of rocks or minerals an cryHtallinecrusts with pronounced radial, fibroua structure.
3.5 White 4. Gray
C— Basal
F— Splintery, con- ch oidal, earthy Brittle
C — Rhombohedral,
perfect (crystals) F — Conchoidal Brittle
C — Pinacoidal, pris- matic F— Conchoidal Brittle
Hardness often greater due to admixture of quartz, feldspar; then tough. Deposits and veins in feldspathic rocks. With kao- lin, pyrite, opal.
Crystals generally curved or sad- dle-shaped with pearly luster. Marble includes some compact varieties. Independent beds; in fissures and cavities; with ore deposits.
Twins common, often pseudohex- agonal — prism and striated base. In cracks and cavities; with ore deposits; deposition from hot springs; in shells. With gypsum, celestite, sulphur, siderite, ser- pentine.
White
C— Indistinct
Similar to aragonite. Divergent
F — Uneven Brittle
columnar structure and higher specific gravity characteristic. In ore deposits; independent masses. With galena, barite, calcite.
White
C— Rotnbohedral,
Curved crystals and rhombohedral
Gray
perfect, conspicu-
F— Conchoidal Brittle
cleavage important. In ore deposits; beds and concretions in limestone, shale. With pyrite, chalcopyrite, galena, tetrahe-
drite, cryolite.
ijGoogIc
B. Hhierals With Hon-Hetallic Luster
Streak
— Dncolored, white, or light gray
Crystallization
Name, Composition, and
Structure
Luster
Color
References
Crystals -C Massive
Transparency
SPHALERITE, variety
Cubic
Adamantine
White
Cleiophane
C— Tetrahedral
Vitreous
Colorless
ZnS
H — Cleavable, compact,
Transparent to
Moses
granular
translucent
Kraua, Dana
33, 201.
Witherite
Orthorhombic
Vitreous
White
Greasy
Grayish
BaCO,
pyramids resembling quartz M— Radial fibrous, com- pact, globular, gran-
transparent
Colorless
122. 382.
ular, lamellar
*Pyromorphite
Hexagonal
Greasy
White
CPriamatic, thick tab-
Adamantine
Gray
Pb,CI(PO,},
ular; rounded bar- rel-shaped; acicular M— Globular, renitorm.
Translucent to opaque
Colorless
1T2, 499.
♦Mimetite
Hexagonal
Greasy
White
C— Prismatic, tabular.
\damantine
Colorless
Pb,C!{AaO,),
rounded barrel- shaped M— Globular, reniform,
173. soo.
2e2
crusts
Colemanite '
Monoclinic
Vitreous
Colorless
C— Prismatic, highly
Dull
Milky
Ca,B,0„,SH,0
modified
Transparent to
whit*
M — Granular, cleavable.
opaque
Yellowish
164, 519.
compact
white
Rhodochrosite
Hexagonal
Vitreous
Reddish white
C — Rhombohedral, rare
Pearly
Yellowish
MnCO,
H — Cleavable, granular, compact, botryoidal.
Translucent
gray
lis, 350.
crusts
Haghestte
Hexagonal
Vitreous
Snow white
C— Rhombohedral, rare
Dull
Gray
MgCO,
M— Compact, granular, porcelain
Translucent to
transparent
Colorless
lie, 353.
*Unconunoo color.
ijGoogle
6. Colokless, White, Or Light Gray Ih Color
Cleavage — C Fracture — F Tenacity
Gravity
Characteristics and
C — Dodecahed ral, Bometimea con spicuous
F— Conchoidal
Brittle
Uncommon color. Color and atreak vary with impurities. In limestone. With tranklinitc, willemite, zincite
C — Indistinct F — Uneven Brittle
Crystals, apparently hexagonal bipyramids; massive, often radial fibrous resembling atrontianite, but heavier. Usually with galena.
Common alteration product ot lead minerals. With galena, cerussite, mimetite, barite, limoo-
White
C— Indistinct
Resembles pyromorphite, but not
F — Uneven Brittle
as common. With lead minerals — galena, pyromorphite.
White
Transparent crystals, resemble
feet, conspicuous F— Uneven, conchoi- dal Brittle
those of datolite, but softer; compact masses look like chalk or porcelain. With gypsum, celestite, quartz.
White
C— Rhombohedral,
May turn brown to black on
perfect, conspicu-
F — Uneven Brittle
exposure, due to MnO,. In ore deposits. With galena, sphalerite, pyrite, alabandite.
White
C— Rhombohedral,
Conchoidal fracture generally
perfect (crystals) F— Conchoidal, con- Tough to brittle
prominent. Compact varietiesare apparently very hard. Dissemi- nated in talcose and chtoritic schists, serpentine, gypsum; inde- pendent beds.
ijGoogIc
HUTERALS WITH NOH-UETALLIC LUSTER Streak— Dncolored, bite, or light gray
C rystalliza tion Structure Crystals Massive — M
' Luster
Transparency
ORITE (Fluor spar)
Cubic
Vitreous
Colorless
C— Cubes, alone or modi-
Transparent to
White
ab'i
fied, well developed M— Cleavable, granular,
translucent
Grayish
Kraui, Dana,
fibrous
103, 320,
Chabazite
Hexagonal
Vitreous
White
C— Rhombohedral, cube-
Colorless
CaA!iSi,0„.8H,0,
etc.
like; lenticular M— Compact
transparent
Gray
2S5. 4S8.
Tetragonal
Apophyllite
Vitreous
Colorless
C— Prismatic, pyramidal,
Pearly
White
H,.K,Ca,CSiO,)„,9H,0
Traneparent to
Yellowish
lar
nearly
white
H— Lamellar, granular,
opaque
compact
280, 452,
Harmotcane
Monoclinic
Vitreous
White
C— Usually twins, pene-
Translucent
Gray
BaAli.0.,.6HA
etc.
trating at 90°
Pectolite, (Pyroxene) (Ca,Na,)i,(SiOj),
CYAHITE, (Disthene, kyanite) AlSiOs
Monoclinic Vitreous White
C — Aeicular, rarely Silky Grayish
terminated; tabular Translucent to
M — Compact radial opaque
fibrous aggregates
Trie! in ic Vitreous White
C — Long, bladed, witli- Translucent to Grayish
out good termi- transparent Colorless
curved and radial grouped H — Coarsely bladed, columnar, fibrous
:y
6. Colorless, White, Or Light Gray Ih Color
Hardness 3 to 6
Hard-
Streak
Cleavage -C Fracture -F Tenacity
Specific
Gravity
Characteristics and
White
Recognized by crystal form, octa-
feet, coDspicuous
hedral cleavage, and hardness.
Brittle
Common gangue of metallic ores, especially galena, sphalerite, cas- siterite; also with calcite, barite.
White
C— Rhombohedral,
Generally in cube-hlte crystals.
not conspicuouB F— Uneven Brittle
it from fluorite. In basic igneous rocks. With analcite, stilbite, heulandite, harmotome.
White
C— Basal, perfect,
Figh-eye opalescence often observ-
F — Uneven Brittle
ed on basal pinacoid. Priem faces vertically striated. In fis- sures and cavities in basic igneous rooks. With natrolite, analcite, laumontite, datolite, prehnite,
native copper, calcitei
White
Cruciform twins, often milky or
F — Uneven Brittle
cloudy. In basic igneous rocks and metalliferous veins. With chabazite, calcite, quartz, adu- laria. PhillipaiU, contains cal- cium replacing barium.
White
Fibers usuaUy divergent, long, and
Grayirfi
coidal F— Uneven, fibrous Brittle
very sharp. In fissures and cavities in baac igneous and metamorphic rocks. With zeolites, prehnite, datolite.
White
C— Pinacoidal, per-
Often with bluish streaks or spots
Brittle
irregularly distributed. Hard- ness varies with direction, 4-5 parallel to long direction, 6-7 at right angles thereto. In gneiss, mica schist. With staurolite, garnet, corundum.
ijGoogle
B. Hiherals With Noh-Hetallic Ldsixr
Streak
— Uncolored, white, or fight gray
CryatallizatioD
Structure
Luster
Color
References
Crystals Massive -M
Transparency
Tetragonal
Adamantine
Gray
C— Pyramidal, small ;
Greasy
White
CaWO.
more rarely tebular
Transparent to
Yellowish
M— Druey crusts, com-
translucent
white
Kraus. Dsna. Pawoni
pact, reniform, gran-
Woll
138, 540. 338
ular, disseminated
ftBtonite (Pyroxene, tabular
Vitreous
White
spar)
C— Tabular, prismatic
Silky
Gray
CaSiO,
M— aeavable, fibrous.
Colorless
granular, compact
translucent
244, 34, 387
Apatite
Hexagonal
Vitreous
White
C— Prismatic, thick tabu-
Greasy
Gray
Ca,F{PO,),
lar
Transparent to
Colorless
M— Compact, fibrous,
translucent
170, 497, 330
noJular, renitorm
HEMIMORPHITE (Calamine)
Orthorhombio
Vitreous
Colorless
C — Thin tabular, pyrami-
Dull
White
dal, hemimorphic.
Transparent to
Gray
liighly modified
opaque
H — Compact, globular.
Btalactitic, fibrous,
granular, cellular.
186. 446. 248
earthy
SBOTHSOinTE
Hexagonal
Vitreous
White
C— Small, usually as
Pearly
Brownish
ZnCO.
druses or crusts
Dull
white
M— Botryoidal, stalac-
Transparent
Gray
to nearly
Colorless
lular, fibrous, com-
opaque
- Iit, 360, 244
pact
Ahalcite
Cubic
Vitreous
Colorless
C— Tetragonal trisocta-
Transparent
White
Na,Al,(SiO,)..2H,0
hedrons, cubes H — Granular, compact
to nearly opaque
Grayish
P
279, 4flO. 415
HatUtT
Orthorhombio
Vitreous
White
C— Slender prismatic,
Silky
Colorless
Na,Al(A10)(SiO,),.2H,0
early square; radia
Transparent to
Grayish
or iuterlaciug groups
translucent
H— Fibrous, granular.
277. 461,_ 41fl
compact
ijGoogle
S. Colokiess, White, Or Light Gray Ih Color
Hardness 3 to 6
Cleavage
Fracture Tenacity
Specific Gravity
White
C —Pyramidal, not
Small, well developed octahedral-
conspicuous
like crystals, usually on quartz;
when massive high specific gravity important. With
Brittle
cassiterite, wolframite, fluorite,
"278
apatite, molybdenite.
White
C — Basal, orthopina-
Fibera may be parallel or diver-
coidal F — Uneven
Brittle
gent. Typical contact mineral' often in crystalline limestone. With garnet, diopside, vesuvian- ite, graphite.
4.Q
White
C— Basal, imperfect
Crystals may be verticaUy striated
F— Couchoidal,
Brittle
and highly modified. In crystal- line limestone; ore deposits, igneous rocks. With quarts, cassiterite, fluorite, wolframite.
White
C— Prismatic
Crystals often in sheaf-like groups
F — Uneven, conchoid-
or druses in cavities. When
may be porous. In limestones. With sphalerite, galena, and especially smithson-
White Gray
CRhom bohedral, not often ob- served
F — Uneven, splintery
Brittle
Cellular varieties are call dry hone. Often mixed with sand, clay, limonite, calcite. With zinc minerals, especially sphal- lerite, hemimorphite. Frequently as a pseudomorph after calcite.
—Uneven, conchoid-
C— Prismatic
F — Uneven Brittle
Good crystals i sures and cavities in basic igneous rocks. With apophyllite, chaba- zite, natrolite, datolite, native copper, prehnite, epidote.
Needle-like crystals have nearly square cross- s ectlon. With chabazite, analcite, apophyllite, stilbite, prehnite, datolite.
jyGoogle
B. Hiherals With Hoh-Hetallic Luster
Streak
— Dncotored, white, or Ugbt gray
CrystalliEation
Name, Compoeition,
and
Structure
Luster
r 1
Crystab -C Massive -M
Thomaonite (ZeoUte)
Orthorhombic
Vitreous
Snow white
C— Prismatic, vertically
Silky
Reddish white
2(Ca,NaJAl,(SiO,),.5H,0
Btriated; divergent
Peariy
Yellowish
groups
Transparent to
white
Mo™
M— Fibrous, columnar,
translucent
Coloriess
KrauB, Dull.
radial; Hpherfcal con-
276, 492.
cretions, compact
DatoUte
Vitreous
Coloriess
C— Prismatic, pyramidal.
Greasy
Greenish
Ca(B.OH)SiO.
tabular, highly
Dull
white
modified
Transparent to
Gray
H — Compact fibrous.
opaque
102, 435
granular, botryojdal
Cubic
Vitreous
White
C— Dodecahedral
Greasy
Gray
Na,Al,(AlCl)(SiO.),
H — Compact, dissemi-
Transparent to
Coloriess
233. 412.
nated grains, nodular
translucent
CancriDite
Hexagonal
Vitreous
White
C— Prismatic, rare
Peariy
YeUowiBh
H.{Na„Ca) .(NaCO,) ,AIi,0,.
H — Compact, lamellar,
Greasy
white
columnar, dissemi-
Transparent to
Gray
233. 411.
nated
translucent
HEPHELn-E (NepheUne,
eteo-
Hexagonal
Greasy
White
lite)
C— Short prismatic, tabu-
Vitreous
Bluish gray
{Na,K).Ali.O,.
lar
Transparent to
Greenish gray
M— Compact, disaerai-
opaque
Coloriess
nated grains
232. 409.
ScapoUte (Wemerite)
Tetragonal
Vitreous
White
C— Thick prismatic,
Greasy
Gray
/ nNa.Ali,0,.a
coarse, often large
Translucent
Greenish gray
M— Compact, fibrous, columnar, granular
270, 426.
ijGoogle
6. COLORLESS, WHm:, OR LIGHT GRAY m COLOR
Cleavage - Fracture — Tenacity
C — Pinacoidal F— Uneven Brittle
Crystals small, usually colorlesB and transparent. When mas- sive, radial fibrous, often mottled or banded. With stilbite, anal- cite, prehnite, calcite.
Crystals glassy, often with greenish tinge; compact masses resemble wedgewood ware or unglazed por- celain; often with reddish, brown- ish, or yellowish streaka and epots. In cracks and cavities in basic igneous rocks. With prehnite, native copper, calcite, zeolites.
White
2,2
May be slightly colored. Recog-
F— Conchoidal, un- Brittle
nized by associates — nephelite, cancrinite, leucite, zircon, feld- spar; not with quartz.
White
C— Priamatic
F— Uneven Brittle
2,5
nephelite, biotite, feldspar, titan-
ite.
White
C— Indistinct
Distinguished from orthoclase by
F— Conchoidal, un- Brittle
interior cleavage and more greasy luster. With feldspar, cancrinite, biotite, Bodalite, zircon, corun- dum; not with quartz.
White
C— Prismatic
Crystals may appear as though
F— Conchoidal Brittle
2,8
fused. Typical contact mineral. In metamorphic rocks, especially granular limestones. With py- roxenes, amphiboles, apatite, gar-
net, biotite.
ijGoogle
B. HHIERALS WITH HOlf-lIETALLIC LUSTER
Streak — Uacolored, white, or Ugbt gray
CrystaHization
Name, Composition, and
Structure
Luster
Color
References
Crystals -C Massive
Transparency
TremoUte
Monoclinic
Silky
White
Co
CaMg.C8iO,).
C— Bladed. without ter-
Vitreous
YeUowish
s
minations
Transparent to
white
O
n
Kraiu. Dana.
Parsoni
opaque
Colorl
252. 400.
granular
Anthophyllite
Vitreous
Gray
C— Prismatic, rare
Pearly
Brownish gray
(Mg,Fe).(SiO,
M— Lamellar, columnar.
Translucent
Greenish gray
2Bi. 398.
fibrous
♦EnsWtite
Orthorhombic
Vitreous
Grayish
CPriamatic, rare
Pearly
Greenish gray
M
Mg,(SiO0,
M— Fibrous, lamellar, co-
Translucent to
YeUowish
&
241. 384.
DIOPSniE
lumnar, compact
opaque
white
o
Monoclinic
Vitreous
Gray
C— Prismatic, thick co-
DuU
Greenish gray
Os
CaMg(SiO,),
lumnar, prism
Transparent
YeUowish
&
angle 87° M— Compact, granular,
to opaque
white Colorless
243. 3S8.
WUkmite
Hexagonal
Vitreous
White
C— Prismatic, rare
Transparent to
Gray
H — Compact, granular,
opaque
Colorless
208. 422.
disseminated grains
OPAL, varieties
Amorphous
Vitreous
Colorless
Precious
pai
M— Reniform, botryoid-
Pearly
Gray
SiO,.xH,0 Milk opal
al, porous, earthy.
Dull
Milk white
Wood opal
compact
Transparent to
Yellowish
Hyalite
opaque
white
SilieioM sinter
TripoliU
Leucite
Pseudocubic
Vitreous
Gray
C— Tetragonal trisoeta-
Greasy
White
K,Ali.O„
hedrons
Translucent to
YeUowish
M— Rounded dissemi-
opaque
white
257. 381,
nated grains
Triclinic
Pearly
White
C— Rare
Vitreous
Yellowish
M— Cleavable, compact, columnar
Translucent
white Gray
173. B03
ijGoogle
6. Colorless, White, Or Light Gray Hi Color
Hardness 3 to 6
Cleavage — C Fracture — F Tenacity
White
C— PriamBtic, con-
spicuous — 124° Brittle
White Grayish
C— Prismatic F— Fibrous Brittle
6. "
White Grayish
"white Gray
C — Prismatic, pina-
coidal F— Uneven Brittle
C— Prismatic; con- BpicuouB basal parting
F— Uneven Brittle
~whit7'
"C— BtTsal
F— Uneven Brittle
e.6
White
F— Conchoidal, con apicuouB when
compact; earthy Brittle
2.9 Silky luster and distinct cleavage 3 , 1 (124°) important. Common con- tact mineral. In limestones, dolomites, schists.
C — Indistinct F — Conchoidal Brittle
C — Basal, conspicu' ous; macropina- coidal, domatic
F — -Uneven
Brittle
Softer when altered. In crystal- line schists. With talc, horn- blende, mica.
Often softer due to alteration to serpentine. In basic igneous rocks. With olivine, serpentine, chondrodite, title.
Prismatic, pseudotetragonal crys- tals, with distinct basal parting. May show colorless and dark green zones. In crystalline lime- stones. With vesuvianite, gar- net, sea polite, spinel, apatite.
Characterized by associates — franklinite, zincite, rhodonite,
Precious opal, with play of colors; milk opal, compact, milk white; wood opal, woody structure; kyaUie, resembles drops of molten glass; Bilicious tirtter, porous or botryoidal; tripoHte, earthy and gritty.
Well developed crystals or rounded grains, disseminated in eruptive rocks. With sanadine, augite, nephelite, olivine.
Usually in cleavable masses, show- ing distinct cleavage in one direction. Resembles orthoelase. With lepidolite, rubellite, topae, petlite.
ijGoogle
B. HIHERALS WITH NOH-HETALLIC LUSTER Streak— Uncolored, while, or light gny
Crystallization Structure CryatalH-C Massive — M
Luster Traneparency
ORTHOCLASE, varietiea Monoclinic
Adularia I KAISi.O, Sanadine OrdinaTy
Vitreous
White
—Prismatic, tliick tabu- Pearly Gray
lar; twins; often large Translucent to Colorless
[ — Cleavable, granular, transparent disseminated
ImCROCLINE KAISijO,
I Oligoclase
..AbjAn,
Triclinic Vitreous Gray
C— Prismatic, thick tabu- Pearly White
lar; twins; often large Translucent to Yellowish M— Cleavable, granular, transparent white
disseminated
Triclinic Vitreous White
CTabular, twins, small Pearly Gray
H — Compact, curved or Transparent to Colorless
divergent translucent
lamellar, granular
Triclinic
C— Tabular, rare M— Compact, cleavable, granular
Vitreous Gray
Pearly White
Greasy Colorless
Transparent to translucent
AbiAnj. . , Ab,An,
' Anorthite
jCaAli,0,{An)
Triclinic Vitreous Gray
C — Thin tabular, often Pearly Greenish gray
with rhombic Translucent White
cross-section to nearly
M — Compact, cleavable, opaque
granular
Triclinic
C — Prismatic, tabular complex
M-ompact, cleavable, lamellar
Vitreous Colorless
"Pearly White]
Transparent to Gray
translucent
:y
I, White, Or Light Gray Hi Color
Hardness over 6
Cleavage — C Fracture — F Tenacity
C — Basal, clinopina- coidal, conspicu- ous, 90°
F — Conchoidal, un-
Brittle
White
C — Basal, braehypin
coidal, conspicu- ous, W 30'
F— Uneven
Brittle
White
C— Basal, brachypir
coidal, conspicu- ous, 86" 24' F— Uneven
Brittle
White
C— Basal, brachypir
coidal, conspicu ous, 86° 32'
F— Uneven
Brittle
Distinguished from other feld- spars by rectangular cleavage and absence of twinning striations. Adularia, opalescent, transpar- ent or slightly cloudy; aanadine, glassy, tabular or square crystals. With quartz, other feldspars, mica, hornblende, sircon.
Resembles orthoclase, but with slightly inclined cleavages and may show twinning striations on basal pinacoid. Occurrence and associates same as for orthoclase.
Inclined cleavages often show fine, parallel twinning striations. Moonstone, opalescent. With quartz, other feldspra, mica,
chlorite, aicinite, beryl, nitile.
Commonly glassy with inclined cleavages showing parallel stria- tions. In granitic rocks. With quartz, other feldspars, mica, garnet, tourmaline. Aventurine oiigoclase or simtone, contains dissemiiiated scales yielding yel- lowish or reddish reflections.
C — Basal, brachypina- coidal, conspicu- ous, 86° i'
Uneven
Brittle
Often with play of colors — yellow, green, blue, red. Inclined cleav- ages are striated. In basic igne- ous rocks. With pyroxenes,
amphiboles.
C — Basal, brae hy pine coidal, conspicu- ous, 85° 50'
F — Uneven
Brittle
Commonly in small, glassy, highly modified crystals. In basic igne- ous rocks; crystalline limestones. With olivine, pyroxenes, pyr- rhotite, magnetite.
:y
B. HUfERALS WITH HOH-HETALLIC LUSTER
Streak
-Oncolored, , or gray
Crystalliaation
Name, Composition, a
nd
Structure
Luster
r
Referencea
Crystals Massive -M
Prehmte
Orthorhombic
Vitreous
White
C— Tabular, prismatic;
Waxy
Greeaisfa
H,Ca,Al,(8iO.),
curved, sheaf-like
Transparent to
white
Moees
groups
translucent
Grayish white
EraoB, Daaa.
M— Botryoidal, stalac-
213, 442.
titic, radial fibrous
Spodumene (Pyroxene)
White
C — Prismatic, tabular.
Pearly
Grayish whits
LiAl(8iO.
vertically striated
Transparent to
Greenish
M— Cleavable, broad
opaque
white
columnar
247. 33.
Sillimanite (Fibrolite)
Orthorhombic
Vitreous
Gray
C— Long, thin, needle-
Silky
Yellowish gray
Al.SiO.
like radiating
Transparent to translucent
Grayish white
188. 433,
40S
Axinite
Triclinic
C — Broad tabular, sharp
Vitreous Transparent to
Pearl gray
R/'R/"B,(8iOJ,
edges
R"-Ca,Fe,Mn,Mg
H — Lamellar, granular
R'" =Al,Fe
213. 441.
ZoiBite
Orthorhombic
Vitreous
Gray
C— Prismatic, deeply
Pearly
Greenish grav
Car4U(A1.0H)(SiO.),
striated, bent, with-
Transparent to
White
out good termina-
opaque
Colorless
H — Columnar, broad
199. 437.
bladed, fibrous Orthorhombic
Diaspore
Vitreous
Coloriesa
C — Broad columnar, tabu-
Pearly
Grayish while
Aio.Oh
lar, rare M— Scaly, confused fibrous or bladed
Transparent to translucent
Lavender gray
92, 34S.
aggregates
Untommon color.
ijGoogle
6. COLORLESS, WHrTE, OR LIGHT GRAY IN COLOR
Hardness over 6
Cleavage Fracture -F Tenacity
C — Basal, not i
epicuouB F — Uneven Brittle
Massive varieties usually have rough cryetalline surfaces and in- ternal radial, fibrous structure. In veins and cavities in basic igneous rocks. With pectolite, datolite, epidote, native copper, ceolites.
C — Prismatic; pina- coidal parting con- spicuous
F — Uneven, splintery
Brittle
C — Hacropinacoidal F — Uneven Brittle
C — Pinacoidal F — Conchoidal Brittle
Commonlj in broad plates due to distinct pinacoidal parting. Prism angle 93°. May have irregular brownish stains. In granitic rocks. With tourmaline, lepidolite, beryl, amblygoiiite.
Crystals often large, bent, striated, with rounded edges, without good terminations, and inter- laced. In metamorphic rocks- mica schist, gneiss. With anda- lusite, sircon, iolite.
Crystals sharp wedge-shaped, glassy, frequently coated and intergrown with green chlorite. With quartz, adularia, albite, tourmaline, hornblende.
— B rachypinacoida], perfect, conspicu-
Deeply furrowed and transversely broken, columnar masses. In crystalline schists. With horn- blende, vesuvianite, cyanite, epi- dote, garnet, feldspar, quartz.
C — B rachypinac oidal,
conspicuous F — Conehoidar Brittle
With coruudum, emery, dolomite, maiarite, chlorite, magnetite.
:y
B. WirERALS WITH HON-HETALLIC LUSTER
Streak — Uacolored, vhlte, or Ugbt gray
Name, CompOBition, and
ClystallJEation Structure Crystals
Massive "M
Luster Transparency
CYAHITE (Disthene, kyaoite)
Triclinic
C — Long, bladed,
ith-
tions; sometimes curved and radially MoMH grouped
KrauB, Dana, PawoM M — Coarsely bladed, 189, 431, 392 Columnar, fibrous
Vitreous White
Translucent to Grayish transparent Colorless
Orthorhombic
Vitreous
White
C — Prisma tic, rough,
Dull
Pearl gray
nearly square, often
Translucent to
Reddish gray
large, without termi-
opaque
nations
H — Columnar, fibrous.
187. 432, 404
nated
GAKHET, variety
Cubic
Vitreous
Colorless
GroaetdaTite
Transparent to
White
CaU(SiO0.
tragonal trisocta-
translucent
Greeniab white
hedrons, alone or in
Yellowish
combination
white
H— Granular, compact.
lamellar, dissemi-
209, 416. 396
nated grains
QUARTZ, Phanerocrystalline
Hexagonal
Vitreous
Colorless
varieties
C— Prismatic, horizon-
Greasy
White
SiO, Rock crystal
tally striated
Transparent to
Gray
Milky quartz
columnar
Ordinary
M— Compact, granular,
translucent
Milky
Cryptocrystalline
Hexagonal
Waxy
White
varieties
CNever in crystals
Vitreous
Gray
Chakednny
H— Nodular, botryoidal.
AgaU
banded, clouded,
opaque
Onyx
concretionary, sta-
Hornsione
lactitic, compact
Chert
70. 324. 372
ijGoogle
S. Colorless, White, Or Light Gray Dt Color
Hardaess over 6
Cleavage Fracture
Tenacity
Specific Gravity
C-— Pinacoidal, per- fect, conspicuous Brittle
Often with bluish streaks or spots, irregularly distributed. Hard- neas varies with direction, 4-5 parallel to long direction, 6-7 at right angles thereto. In gneiss, mica schist. With staurolite, corundum, garnet.
C — Prismatic F — Uneven BritUe
Due to alteration, surface may be coated with scales of mica, then softer. In met amorphic rocks, often as rounded or knotty pro- jections. With cyanite, sillima- nite, garnet.
C— Dodecahedral, u
ally indistinct F— Conchoidal, UU'
Typical contact mineral, in crys- talline limestohea and dolomites. With wollastonite, vesuvianite, diopside, sea polite.
C — Indistinct F — Conchoidal, c
spicuous Brittle
C — Indistinct F — Conchoidal, c(
spicuous Brittle to tough
Characteristic conchoidal fracture and glassy luster. Rock crystal, colorless, or nearly so, and gen- erally crystallized; milky quartz, milk white and nearly opaque.
Not as glassy as phancrocrystal- line varieties. Chalcedony, horn- stone, chert, uniform in color; agate, onyx, clouded or banded. To distinguish, see references.
:y
B. mnBRALS WITH hoh-hetallic luster
Streakuncolored, white, or gray
Crystallizatioa Structure Crystals -C Massive— M
Transparency
QUARTZ, Clastic varieties Sand S lOj Sandstone
Ilacoiumile QuarUUe
Hexagonal Vitreous Gray
MGraina, fragments, Dull White
either loose or Translucent to
strongly consoli- opaque
Boracite
Mg,CI,B..O„
182. 618,
*Iolite (Cordierite)
(Mg,Fe),Al,(OH),(Si,0,).
Danburite
CaB,(SiO.),
207, 43
♦Tourmalihe
M.'Al,(B.OH)i<0„ M'=Na,K,Li,Mg,Fe
Phcnacite
BeiSiO.
Pseudocubic
C — Tetrahedral, cubical, small, well developed
H — Compact, nodular, fine fibrous
Orthorhombic
C— Short prismatic, pseudohexagonal
H — Compact, dissemi- nated grains, granu-
Orthorhombic
C — Prismatic, highly modified
H — Disseminated
Hexagonal
CPrismalic, vertically striated; terminated with broken or tbom- bohedral-like sur-
Hexagonal
C — Rhombohedral, pris- matic, pyramidal, lenticular; highly modified
Vitreous Colorless
Transparent to White
opaque Gray
Vitreous Gray
Dull Bluish
Transparent to gray
translucent Colorless
eous Colorless
Greaaj Yellowish Transparent to white
anslucent
V t eous Colorless
Transparent to White
t an lucent Gray
Vitreous Colorless
Transparent to White translucent Yellowish
Zircoh
ZrSiO.
Tetragonal Adamantine Brownish
C — Square prisms with Vitreous gray
bipyramids, small, Pearly Lavender
well developed Transparent to gray
H — Irregular lumps, opaque Colorless
:y
S. COLORLESS, WHITE, OR LIGHT GRAY Q( COLOR Hardness over 6
Cleavage -C Fracture —F Tenacity
Characteristics and
C — Indistinct F— Uneven Brittle to tougt
SaTid, loose, unconsolidated grains; saTidston, consolidated sand; itaeolumiU, flexible sandstone; quartzUe, metamorphosed sand-
7,
White
C— None
2,9
F — Conchoidal,
mon; compact masses resemble
uneven
fine grained marble. With gyp-
Brittle
sum, anhydrite, halite, camallite.
White
C— Pinacoidal, some-
2,6
When fresh, glassy and hard
times conspicuous
resembling quartz; usually alter- ed, then dull and softer. With quartz, feldspar, hornblende, sil-
Brittle
limanite, andalusite.
White
2:9
Resembles topaz, but cleavage not
7.B
F— Uneven, conchoid- al
as perfect. With calcite, dolo- mite, mica, microcline, pyroxene.
w;hite
Brittle
tourmaline.
C— None
Spherical triangular cross-section.
7.B
F— Uneven, conchoid-
3,2
Often with zones of red or green.
C — Indistinct — Conchoidal Brittle
In pegmatites; metamorphie rocks; alluvial deposits. With quartz, feldspar, cassiterite, beryl, topaz, fluorite. Distinguished from quartz and topaz by crystal form and cleav- age. In pegmatites and meta- morphie rocks. With quartz, topaz, beryl, amazonstone, chrys- oberyl.
In acid igneous rocks — granite, syenite; alluvial deposits, with gold, spinel, corundum, garnet. Jargon, colorless or smoky.
ijGoogle
B. MDfERALS WITH HOIT-HETAIXIC LVSTER
Streak
— Dncolored, white, or tight gray
Crystalliiiation
Dd
Structure
Luster
References
Crystala -C
Transparency
Massiva-M
Bertl
HexBgoasI
Vitreous
White
C— Long prismatic, often
Transparent to
Yellowish
Be,Al,(SiO,)
verticaUy striated,
translucent
white
large
Greenish
KnuB,
DllTll.
Puraom
M — Columnar, granular.
white
2S7.
3B1
compact
Coloriess
Law80Nitb
Orthorhombic
Vitreous
Bluish .
C — Prismatic, tabular,
Greasy
white
Ca(Al.OH),(Si0,)
Eix-sided
Transparent to
Bluish
H — Lenticular platea
opaque
gray
Colorless
Ib5.
447,
Topaz
Vtr u
Colorless
C— Prismatic, vertically
T nsp ntto
White
AU(F,OH)iO.
striated, highly modified H — Compact, granular, tolled fragments
p q
Grayish
Chrysoberyl
Orthorhombic
Vitreous
Greenish
C— Tabular; heart
Greasy
white
Be(A10,),
shaped and pseudo-
Transparent to
Yellowish
hexagonal twins
translucent
white
MFragments, loose
161,
3M
rounded grains
CORnNDDH
Hexagonal
Vitreous
Gray
C— Prismatic, tabular.
Greenish gray
Ai.O.
pyramidal, rhombo- hedral; rough or rounded barrel- Bhaped H — Compact, granular.
transparent
Bluish gray
84,
34S
lamellar
Diamohd
Cubic
Adamantine
Coloriess
Greasy
Gray
G
3,
27 J.
tahedrons, usuaUy with curved surfaces H — Rounded or irregular grains or pebbles, often with internal radial structure
Transparent to translucent
White
cGoogle
fi. COLORLESS, WHITE, OR LIGHT GRAV m COLOR
Cleavage — C Fracture -F Tenacity
Specific Gravity
C — Indistinct F — Concboidal,
Crystals usualJy simple — prism and base. In granitic rocks, mica Bctists, clay elates. With quartz, feldspars, mica, chryso- beryl, garnet, topaz, tourmaline.
8. White
C — Pinacoidal, psrfect
F— Uneven
Brittle
C — Basal, perfect,
conspicuous F — Coocfaoidal, un-
Fresh cryetals are colorless, due to alteration covered with white or gray spots. Resembles corun- dum but not as heavy. In schists with actinolite, chiorite, margarite, epidote, garnet.
Crystals usually developed on one end only. Massive varieties dis- tinguished from quartz by higher specific gravity and basal cleav- age. In veins and cavities in granitic rocks; alluvial deposits. With caeaiterite, tourmaline, fiuor- ite, beryl, scheelite, wolframite.
Crystals disseminated as plates, often with feather-like or radial striations. In mica schists granite, gneiss, placers. With beryl, garnet, tourmaline, siUi- manite.
CNone, nearly rect- angular basal and rhombohedral partings conspicu- ous; often striated
F — Conchoidal
Brittle to tough
3.9 When
often multicolored — blue, green, red, yellow. In limestones, granites, syenites, schists, alluvial deposits. With magnetite, uephelite, mica, spinel, chlorite.
10. Ash gray C— Octahedral, per- 3.5 May be tinged yellow, brown, red.
feet, usually (
spicuous F — Conchoidal Brittle
blue. In serpentine rocks— berlite, peridotite, called blue ground; placers, with pyrope, magnetite, chromite, cassiterite, zircon, gold.
JyGoOgIc
ijGoogle
Index.
This iDdex contains references to minerala only, for general terms consult the glossary, page 7.
Actinolite, 134, 148
schist, 135 Adularia, 238, 239 Agate, 120, 121, 202, 203, 242, 243 Alabandite, 18 Alabaster, 212, 213 Albite, 238
Alexanderite, 160, 161 Allanite, 24, 62, 74, 84, 168, 196 Allophane, 138, 178 Almandite, 28, 29, 86, 87, 118, 119, 2i
Alum stooe, 226 Alunite, 226 Amalgam, 40 Amazonstone, 150 Amber, 100, 178 Amblygonite, 150, 196, 236 Amethyst, 120, 121, 166, 157
oriental, 122, 123, 160, 161 Amphiboles, 22, 72, 82, 114, 128, 130, i;
148, 152, 176, 194, 216, 236 Analcite, 112, 232 Anatase, 24, 62, 84, 196 Andaluaite, 118, 154, 200, 224, 242 Andradite, 28, 29, 86, 87, 118, 119, 1!
157, 202, 203 Angleaite, 140, 182, 222 Anhydrite, 78, 104, 138, 222 Annabergite, 124, 132 Anorthit*, 238 Anthophyllit, 194, 236 Anthracite coal, 32, 68 Anthraconite, 78, 180 Antimony, 40 Apatite, 78, 80, 110, 144, 176, 184, 1!
216, 224, 232 Apophyllite, 110, 230
Aquamarine, 158 Aragonite, 108, 142, 186, 226 Argentite, 34 Arsenic, 36, 44 Arsenopyrite, 46 Asbestos, 132, 172, 173, 208 Asphalt, 30, 68 Atacamite, 70, 126 Augite, 22, 72, 82, 130, 148 Aventurine, 120, 121, 202, 203
oligockse, 239 Axinite, 152, 198, 240 Asurite, 128
Barite, 102, 104, 136, 140, 178, 182, 218,
Bauxite, 92, 162, 210 Beryl, 158, 206, 246
common, 15S Biotite, 16, 78, 136 Bismuth, 40, 54 Bismuthinite, 42 Bituminous coal, 32, 68 Black jack, 18, 70, 80
lead, 30, 68 Blue ground, 91, 246
vitriol, 126 Bog iron ore, 48, 49, 58, 1
163, 166, 167 Boracite, 166, 204, 244 Borax, 214 Bomile, 54, 66 Bort, 90, 91 Bournonite, 34 Braunite, 38 Brittle silver ore, 32 Broohantite, 126 Bronzite, 148, 194
:y
Brookite, 24, 64, 74, 84, 168, 196 Brown clay ironstone, 68, 59, 60, 61 163, 166, 167
coal, 16
ocher, 68, 69 Brucite, 134, 214
. Calamine, 144, 190, 232 Calaverite, 48, 54 Calcite, 78, 102, 138, 180, 210, 220 Calomel, 172, 208 Cancrinito, 114, 146, 192, 234 Carbonado, 90, 91 Carnainte, 98, 170, 208 Camelian, 120, 121 Caasiterite, 28, 64, 76, 86, 98, 118,
Cat's
ordinary, 28, 64
eye.
156, 167, 160, 161, 202,
Celeatite, 104, 138, 182, 222
Cerargyrite, 130, 170, 208
CeniBsite, 80, 182, 222
Chabazite, 108, 188, 220
Chalcanthite, 126, 136
Chalcedony, 88, 89, 156, 157, 202, 203,
242, 243 Chalcocite, 34 Chalcopyrite, 50, 56 Chalcotrichite, 60, 94 Chalk, 210, 211
French, 210, 211 Chert, 242 Chiastolite, 225 Chile saltpeter, 174, 212 China clay, 210 Chloanthite, 44 Chlorastrolite, 150 Chlorite, 124, 132 Chloritoid, 74, 86, 130, 154 Chondrodite, 116, 1S8 Chromite, 24, 74 Chrysoberyl, 160, 206, 246
ordinary, 160 Chryaocoila, 124, 126, 134, 140 Chrysolite, 156 Chryaoprase, 156, 157 Chrysotile, 132, 172, 185, 208 Cinnabar, 58, 92, 164 Cleiophane, 228 Clinochlorite, 124, 132
Coal, anthracite, 32, 68
bituminouB, 32, 68
brown, 16, 68 Cobalt bloom, 92 Cobaltite, 44 Cog-wheel ore, 34 Coleroanite, 228 Columbite, 26, 38 Copiapite, 164, 212 Copper, 54, 58 Copperas, 134, 212 Coquina, 220 Cordierite, 168, 244 Corundum, 28, 38, 76, 122, 160, 206, 246
common, 122, 160, 206 Covelhte, 66, 124 Crocoite, 92
Cryolite, 78, 102, 178, 218 Cuprite, 18, 60, 70, 94 Cyanite, 144, 154, 230, 242
D
Danburite, 204, 244 Datohte, 112, 146, 192, 234 Desmine, 106, 182, 224 Diamond, 90, 246
proper, 90, 91 Diaspore, 164, 200,240 Diopside, 148, 194, 236 Dioptase, 128
Diathene, 144, 164, 230, 242 Dog tooth spar, 180, 220 Dolomite, 80, 106, 184, 226 Domeykite, 44, 50, 54 Dry bone, 191 Dyscrasite, 40 Dyaluite, 30, 88
E Elaeolite, 114, 146, 194, 234 Emerald. 158
oriental, 160, 161 Emery, 28, 38, 76 Enargite, 34 Enstatite, 194, 236 Epidote, 84, 116, 154, 198 Epsom salt, 214 Epsomite, 214 Erythrite, 92
Feldspar, 84, 116, 150, 198, '. FBTgusonite, 26
L),9,:z;cCyG00le
Fibrolite, 152, 198, 240
FUnt, 88, 89, 202, 203
Flos fern, 226
Fluorite, 82, 108, 142, 188, 230
Fluor epar, 82, 108, 142, 188, 230
Fool's gold, 52, 56
Fowlerite, 115, 195
Franklinite, 26, 38
GadoUnite, 28, 64, 36, 200
Gahnite, 30, 88, 158, 206
Galena, 34, 42
Galenite, 34, 42
Garnet, 28, 86, 118, 156, 202, 242
Garaierite, 124, 134
Gibbsito, 100, 104, 136, 138, 178, 180, 218,
Glauberite, 100, 176, 216 Glauber salt, 210 GlaucoDite, 124, 130 Glaucophaue, 130, 152 Goethite, 20, 50, 62, 72, 96, 168 Gold, 48, 64 Graphic tellurium, 41 Graphite, 30 Greenockit, 164 Green sand, 125, 131 GroBsularite, 118, 119, 156, 157, 1
Griinerite, 135, 176, 216 Gypaum, 76, 98, 174, 212 ordinary, 174, 212
Hahte, 76, 100, 134, 174, 214
Harmotome, 108, 183, 230
Ha usma unite, 20
Heavy spar, 102, 104, 136, 140, 178, 182,
218, 222 HeUotrope, 120, 121, 156, 157 Hematite, 16, 24, 26, 58, 60, 92, 94
argillaceous, 24, 25, 26, 27, 60, 61, 94,95
compact, 24, 25, 26, 27, 60, 61, 94, 95
toBsiliferouB, 58, 59, 92, 93
oolitic, 58, 59, 92, 93 Hemimorphite, 144, 190, 232 Hercynite, 30, 76 Heulandite, 106, 182, 224 Hexagonite, 114 Hiddenit, 152
Hornblende, 22, 72, 82, 128, 148 Horn silver, 130, 170, 208
stone, 242, 243 Huebnerite, 20, 62, 72, 82, 96, 110, 1
Hyacinth, 123, 205 Hyalite, 236, 237 HydrargilUte, 100, 104, 136, 138, 173, 1
218, 220 Hypersthene, 32, 82, 148, 194
Iceland spar, 220 Ilmenite, 22, 36 Ilvaite, 38, 74 lolite, 158, 244 Iridoamium, 42 Iron, native, 36 pyrites, 52, 56 white, 46, 50, 56 Isinglass, 176, 216 Itacolumite, 244, 245
Jade, 149
Jamesonite, 33, 43
Jargon, 245
Jasper, 120, 121, 202, 203
Jet, 17, 69
Kainite, 100, 178, 218 Kaolin, 98, 132, 172, 210 Kaolinite, 98, 132, 172, 210 Kieserite, 178, 218 KuuEite, 120 Kyaoite, 144, 154, 230, 242
Labradorite, 84, 150, 238 Lapis lazuli, 128, 144 Laumontitc, 98, 106, 184, 234 Lawsonite, 246 Lazuli te, 146 Lazurite, 128, 144 Leadhiilite, 136, 176, 218 LepidoUte, 100, 106, 216, 224 Leucite, 236 Lignite, 16, 68 Limestone, 78, 180, 220 Limonite, 30, 48, 58, 60, 162, 166 compact, 60, 61, 166, 167
zjcCyGoOgIC
Linnaeite, 44 L51Iingit, 44
Magnesite, 80, I8S, 228 Magnetite, 38
-grOnerite schist, 135, 177, 217 Malachite, 128 MaDganite, IS
Marble, 78, 107, 180, 185, 220, 227 Marcasite, 46, 50, 66 Margarite, 106, 184, 224 Marl, 210, 211 Martite, 24, 25, 26, 27 Meerschaum, 214 Melaconit, 32, 68 Melanterite, 134, 212 Menaccanite, 22, 36 Mercury, 40 Mica, 136, 176, 216, 224
black, 16, 78
bronze, 102
Uthium, 100, 106
ruled, 175, 217 Microcline, 150, 238 Itfillerite, 50, 54 Mimetite, 188, 228 Mineral pitch, 30, 68
wax, 16, 68 Mirabilite, 210 Miey, 164, 212 Mohawkite, 45, 51, 55 Molybdenite, 30, 42 Monazite, 112, 192
Mountain cork, 173, 209 leather, 173, 20a wood, 173, 209
Muscovite, 176, 216
N
Nail-bead spar, 180, 220
Natrolite,112,192,232
Natron, 208
Nepheline, 114, 146, 194, 234
Nephelite, 114, 146, 194, 234
Nephrite, 149
Niecolite, 56, 66
Nickel bloom, 124, 132
Niter, 212
Ocher, brown, 58, 59, 162, 163
red, 58, 59, 92, 93
yellow, 48, 49, 162, 163 Octahedrite, 24, 62, 84, 196 Oligockse, 238 Olivine, 118, 156,212 Olivenite, 126, 164 Onyx, 88, 89, 242, 243 Opal, 116, 160, 172, 196, 208, 236
fire, 116, 117
jasper, 116, 117, 196, 197
milk, 236, 237
precious, 151, 196, 197, 236, 237
wood, 196, 197, 236, 237 Orangite, 20, 21, 48, 70, 168 Orpiment, 162
Orthite, 24, 62, 74, 84, 168, 196 Orthoclase, 116, 198, 238
ordinary, 238 Ozocerite, 16, 68
P Paraffin, native, 16, 68 Paragonite, 176, 216 Pearl spar, 226 PectoUte, 230 Pentlandite, 50, 56 Peridot, 156
Perovskite, 24, 64, 84, 196 Pharmacol! te, 214 Phenacite, 120, 204, 244 Phillipaite, 109, 189, 231 Phlogopite, 102, 136, 176 Phosphate rock, 78, 80, 176, 184, 216 Picotite, 30, 76, 170 Pitchblende, 18, 36, 60, 66, 70 Plagioclase, 238 Plasma, 166, 157 Platinum, 42
Pleonasfe, 30, 88, 158, 206 Plumbago, 30, 68 Polybasite, 32 Polyhalite, 104, 180, 220 Prase, 156, 157 Prehnite, 152, 240 Prochlorite, 124 Proustite, 58, 92 Psilomelane, 22, 36, 72 Purple copper ore,'66 Pyrargyrite, 16, 58, 94 Pyrite, 52, 56
.7 o Ogle
Pyroluaite, 30
Pyromorphit*, 128, 142, 166, 186, 228
PjTope, 118, 119
Pyrophyllite, 130, 170, 210
Pyroxenes, 22, 72, 82, 110, 114, 120, 130,
148, 152, 190, 194, 230, 232,
236, 240 Pyrrhotite, 56, 66
Quartz, 88, 120, 156, 202, 204, 242, 244
chloritic, 156, 157
ferrugiQOUS, 120, 121, 202, 203 '
milky, 242, 243
ordinary, 242, 243
rose, 120, 121
smoky, 88, 202, 203 Quartzite, 120, 121, 204, 205, 244, 245 Quicksilver, 40
Realgar, 92, 162
Red ocher, 58, 59, 92, 93
Rhodochrosite, 108, 142, 188, 228
Rhodonite, 114, 194
Rock crystal, 242
salt, 76, 100, 134, 174, 214 Rubellite, 120 Rubicelle, 122, 123 Ruby, 122, 123 Rut[le, 26,64,74,86,96, 116, 170,200
Sal Ammoniac, 174, 210
Salt peter, 212 Samarskite, 24 Sand, 120, 121, 204, 205, 244, 245
stone, 120, 121, 204, 205, 244, 245 Sanidine, 23S Sapphire, 160, 161 Sardonyx, 120, 121
Satin spar, 76, 77, 174, 175, 212, 213, 220 Scapolite, 114, 146, 234 Scheelite, 110, 144, 190, 232 Seorodite, 142, 186 Selenite, 76, 77, 174, 175, 212, 213 Senarmontite, 216 Sepiolite, 214
Serpentine, 80, 106, 140, 184 Siderite, 18, 70, 166, 1S6, 226 Silicious sinter, lOB, 236, 237 Sillimanite, 152, 198, 240
Silver, 16, 40
amalgam, 40
brittle ore, 32
dark ruby ore, 17, 59, 95
glance, 34
light ruby ore, 59, 93 Smaltite, 44
Smithsonite, 144, 190, 232 Soapatone, 98, 99, 132, 133, 172, 173,
210,211 Soda, 208
niter, 174, 212 SodaUte, 114, 146, 234 Specular iron ore, 16, 24, 25, 26, 27 Spessartite, 118, 119, 202, 203 Sphalerite, 18, 48, 60, 70, 80, 94, 108, 186,
Sphene, 20, 82, 112, 146, 192 Spinel, 30, 76, 88, 122, 158, 170, 206
almandine, 122, 123
balaa, 122, 123
blue, 158
chloro, 158
ruby, 122, 123 Spodumene, 120, 152, 240 Stagmite, 78, ISO, 220 Sta unite, 36 Staurolite, 88, 204
Steatite, 99, 132, 133, 172, 173, 210, 211 Stephanite, 32 Stibnite, 32, 42 Stilbite, 106, 182, 224 Stream tin, 28, 29, 64, 65, 77, 86, 99,
119, 171, 201 Stromeyerite, 34 Strontianite, 142, 186, 226 Struvite, 174, 212 Succinite, 100, 178 Sulphur, 162, 174 Sunstone, 239 Sylvanite, 40 Sylvite, 100, 134, 174, 214
Tabular spar, 110, 190, 232 Talc, 98, 132, 172, 210
foliated, 98, 99, 132, 133, 210, 211 Tantalite, 26, 27, 38, 39 Tellurium, graphic, 41 Tenorite, 32 Tetrahedrite, 18, 34 Thinohte, 180, 220
:y
Thomaonite, 112, 192, 234
Thorite, 20, 48, 70, 168
Thulite, 116
Tinkal, 214
Titanite, 20, 82, 112, 146, 192
Topaz, 122, 158, 206, 246
false, 202, 203
oriental, 206, 207 TourmaUne, 28, 88, 120, 158, 204, 244 Travertine, 78, 180, 220 Tremolite, U4
Tripolite, 172, 198, 208, 236, 237 Trona, 218
Troostite, 114, 116, 196 Tutquoie, 130, 160
U Ulexite, 208 Uraninite, 18, 36, 60, 66, 70
Uvarovite, 156, 157
Vanadinite, 94, 104, 164, 180 Verd-antique, 141 Veauvianite, 156, 202 Vivianite, 124, 132, 212
Wad, 16, 32, 58, 66, 68, 162
Wavellite, 80, 140, 184, 226 Wemerite, 114, 146, 234 Willemite, 114, 150, 196, 236 Witherite, 228
Wolframite, 22, 36, 64, 66, 72, 96, 168 Wollastonite, 110, 190, 232 Wood tin, 64, 98, 170, 201 Wulfenite, 94, 102, 138, 164, 180, 220
Xenotime, 96, 108, 1
Yellow ocher, 48, 49
Zaratite, 126
Zeolites, 98, 106, 108, 110, 112,182,184,
188, 192, 224, 230, 232, 234 Zincite, 48, 62, 96, 166 Zircon, 122, 20:4, 242 Zoisit, 116, 152, 198, 240
:y
ijGoogle
ijGoogle
ijGoogle
ijGoogle
m
.jGoogle
ijGoogle