Part 19

+-----------------+--------------+-------------+-----------------------+ |=Name of Mineral=| =Color= | =Streak= | =Cleavage or | | | | | Fracture= | +-----------------+--------------+-------------+-----------------------+ |=Amphibole.= |Black or light|White. |Perfect in two direc- | | |to dark green.| |tions at angle of 124°.| | | | | | |=Arsenopyrite.= |Silver, |Black. |Good in two directions | | |yellowish, or | |at an angle of 112°. | | |light grayish | |Not evident on fine | | |white. | |grained material. | | | | | | |=Barite.= |White, yellow,|White. |Perfect in one direc- | | |blue or brown.| |tion; two other good | | | | |cleavages at right | | | | |angles to the first and| | | | |at 101° with each | | | | |other. | | | | | | |=Biotite.= |Black or dark |White. |Very perfect in one di-| | |brown. | |rection, yielding thin | | | | |sheets. | | | | | | |=Calcite.= |Colorless or |White. |Perfect in three di- | | |white when | |rections at angles of | | |pure, all | |about 105° or 75°. | | |colors when | | | | |impure. | | | | | | | | |=Chalcocite.= |Dark gray. |Lead-gray. |No cleavage, smooth | | |Tarnishes | |conchoidal fracture. | | |black or | | | | |green. | | | | | | | | |=Chalcopyrite.= |Bright brass- |Greenish |No cleavage. Uneven | | |yellow. Often |black. |fracture. | | |tarnished iri-| | | | |descent. | | | | | | | | |=Copper.= |Copper-red. |Copper-red. |No cleavage. Hackly | | |Tarnishes | |fracture. | | |green to | | | | |black. | | | | | | | | |=Corundum.= |All colors; |White. |Often parts readily | | |usually gray | |into almost rectangular| | |or brown when | |pieces whose faces are | | |massive. | |cross-hatched. | | | | | | |=Epidote.= |Dark green or |White. |Perfect in one direc- | | |greenish brown| |tion. | | |(crystals) to | | | | |light yellow- | | | | |ish green. | | | | | | | | |=Fluorite.= |All colors; |White. |Cleaves easily into | | |green, violet,| |octahedrons, i. e., | | |purple, color-| |in four directions, at | | |less and | |angles of 109° or 71°. | | |white, the | | | | |commoner. | | | | | | | | |=Galenite.= |Bluish lead, |Lead-gray. |Perfect cubical, i. e.,| | |gray. Tar- | |in three directions at | | |nishes black. | |angle of 90°. | | | | | | |=Garnet.= |Commonly some |White. |No cleavage. Uneven | | |shade of red; | |fracture. | | |also brown, | | | | |yellow, white,| | | | |black, green. | | | | | | | | |=Gold.= |Golden yellow |Yellow to |No cleavage. Hackly | | |to nearly |nearly white.|fracture. | | |silver-white. | | | | | | | | |=Graphite.= |Dark gray to |Dark gray. |Perfect in one direc- | | |black. | |tion. Cleavage faces | | | | |are apt to be curved. | | | | |Not shown if finely | | | | |granular. | | | | | | |=Gypsum.= |White, gray, |White. |Very perfect in one | | |red, yellow or| |direction; two others | | |other tints | |show as cracks at angle| | |due to | |of 114°, on the perfect| | |impurities. | |cleavage faces. | | | | | | |=Halite.= |Colorless or |White. |Perfect cubic i. e., in| | |white when | |three directions at | | |pure. Yellow, | |angle of 90°. | | |brown, red, | | | | |etc., when | | | | |impure. | | | | | | | | |=Hematite.= |Black when |Red. |No cleavage; may have a| | |metallic; red-| |parting in one direc- | | |dish black | |tion producing a platy | | |when dull, red| |structure. Uneven | | |when earthy. | |fracture. | | | | | | |=Limonite.= |Yellow, brown |Yellow or |No cleavage. Uneven | | |or nearly |yellowish |fracture. | | |black. |brown. | | | | | | | |=Magnetite.= |Iron-black. |Black. |No cleavage. Sometimes | | | | |parts in four direc- | | | | |tions at angles of 109°| | | | |and 71°. Uneven to sub-| | | | |conchoidal fracture. | | | | | | |=Malachite.= |Green, often |Green. Paler |No cleavage. Uneven | | |nearly black |than the |fracture. | | |on exposed |color. | | | |surfaces. | | | | | | | | |=Muscovite.= |White or light|White. |Very perfect in one | | |tints of other| |direction, yielding | | |colors, par- | |thin sheets. | | |ticularly | | | | |gray, brown or| | | | |green. | | | | | | | | |=Orthoclase.= |Flesh-red, |White. |In two directions at | | |gray, yellow, | |angle of 90°, one di- | | |white or | |rection slightly less | | |colorless. | |perfect than the other.| | | | | | |=Pyrite.= |Pale to deep |Black. |No cleavage. Conchoidal| | |brass-yellow. | |to uneven fracture. | | |Tarnishes | | | | |brown or | | | | |iridescent. | | | | | | | | |=Pyrolusite.= |Black to dark |Sooty black. |May appear to have good| | |steel-gray. | |cleavage in one direc- | | | | |tion but usually shows | | | | |none. | | | | | | |=Pyroxene.= |Black or light|White to |Poor in two directions | | |to dark green.|greenish. |at angle of nearly 90°.| | | | |May have a fine platy | | | | |parting. | | | | | | |=Quartz.= (Pheno-|White or |White or |No cleavage. Single | |crystalline). |colorless when|light tints. |crystal has conchoidal | | |pure. All | |fracture, otherwise the| | |colors when | |fracture is uneven. | | |impure. | | | | | | | | |=Quartz.= (Cryp- |... |... |No cleavage. Conchoidal| |tocrystalline). | | |fracture. | | | | | | |=Serpentine.= |Light to dark |White. No |Conchoidal fracture | | |green, yellow,|cleavage. |when massive. | | |brownish red, | | | | |variegated. | | | | | | | | |=Siderite.= |Light to dark |White to |Very perfect in three | | |brown or gray.|yellowish. |directions at angle of | | |Tarnishes red-| |107° and 73°. Not | | |dish brown or | |evident when fine | | |brownish | |grained. | | |black. | | | | | | | | |=Sphalerite.= |Commonly yel- |White, yellow|Very perfect in six | | |low, brown, |or brown. |directions at angles of| | |black or red; | |60°, 90° and 120°. | | |sometimes | | | | |green or | | | | |white. | | | | | | | | |=Stibnite.= |Light gray. |Lead-gray. |Perfect in one direc- | | |Cleavage faces| |tion, yielding blade- | | |appear silver | |like strips which are | | |white when | |bent or hatched perpen-| | |reflecting | |dicular to their | | |light. | |length. | | | | | | |=Talc.= |White, light |White to |Perfect in one direc- | | |green, gray; |greenish. |tion, yielding thin | | |other colors | |flexible plates. Not | | |when impure. | |shown on the fine | | | | |grained soapstone. | | | | | | |=Tetrahedrite.= |Gray. |Gray, brown, |No cleavage. Uneven, | | | |or reddish. |granular fracture. | | | | | | |=Tourmaline.= |All colors. |White. |No cleavage. Uneven to | | |Interior and | |poor conchoidal | | |exterior or | |fracture. | | |opposite ends | | | | |of a crystal | | | | |may differ in | | | | |color. | | | | | | | | |=Zoisite.= |White, gray, |Uncolored. |Parallel cleavage; | | |yellow, brown.| |sometimes fibrous. | +-----------------+--------------+-------------+-----------------------+