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List of Minerals

A list of well-known minerals, their chemical compositions, and their uses.
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Apatite
Calcium fluorophosphate. Used as a source of phosphate for fertilizer and munitions. Vitreous to greasy luster, green to yellowish green, H=5, G=3.2, conchoidal fracture, streak white, crystals common. Nonmetallic light-color, does not scratch glass, no cleavage.
Augite
Iron magnesium aluminosilicate. Has no commercial use, but is an important rock-forming mineral. Nonmetallic dark color mineral, scratches glass, shows cleavage in 2 planes near 90 degrees. Vitreous to dull luster, dark green to black color, H=5.5 - 6, G=3.4, streak greenish white.
Biotite
Iron magnesium aluminosilicate. Has no commercial use; is an important rock-forming mineral. Nonmetallic dark color, does not scratch glass. Vitreous to pearly luster, black to brown color, H=2.5, G=3.4, perfect basal cleavage, streak white to gray.
Calcite
Calcium carbonate. Used for portland cement and is an important rock-forming mineral. Nonmetallic, does not scratch glass, shows rhombohedral cleavage. Vitreous luster, variable color (usually colorless to white), H=3, G=2.7, fizzes in HCl, double refraction if clear crystal, streak white.
Chalcopyrite
Copper iron sulfide. Used as a source of copper. Metallic luster. Streaks greenish black, brassy yellow color (may tarnish), H=3.5 - 4, G=4.2, fracture uneven to conchoidal.
Fluorite
Calcium fluoride. Used as a source for toothpaste and rat poison. Nonmetallic light color, does not scratch glass, shows octahedral cleavage. Virteous luster, variable color (clear to purple, green to yellow) H=4, G=3.1, streak white.
Galena
Lead sulfide. Used as a source of lead. Metallic luster, streaks lead gray. Lead to silver gray color, H=2.5, G=7.5, cubic cleavage.
Garnet
Iron magnesium aluminosilicate. Used as an abrasive, in jewelry, and is the birthstone for January. Nonmetallic dark color, scratches glass, no cleavage. Vitreous luster, reddish brown color, H=7 - 7.5, G=4.3, conchoidal fracture, dodecahedron crystals.
Graphite
Carbon. Used as pencil "lead", lubricants, and electrodes. Metallic to dull waxy luster, gray to black color, H=1 - 2, G=2.2, uneven fracture, greasy feel, smudges fingers.
Gypsum
There are two varieties of this mineral. Calcium sulfate. Used for sheet rock, wall board, toothpaste, and plaster of Paris. Nonmetallic light color, soft, does not scratch glass. Vitreous luster, variable color (usually clear to white), H=2, G=2.3, three planes of cleavage (good in one direction), streak white.
Halite
Sodium chloride. Used as a food preservative and in seasoning. Nonmetallic light color, soft, does not scratch glass, shows cubic cleavage. Vitreous luster, variable color (usually clear to gray), H=2.5, G=2.1, streak white, salty taste.
Hematite
Iron oxide. Used as a source of iron. Nonmetallic dark color, hard scratches glass, no cleavage. Dull earthy luster, brownish red color (oolitic appearance), H=5 -6, (earthy variety may be extremely soft) G=5.3, uneven fracture, streak red.
Hornblende
Iron magnesium aluminosilicate. Has no commercial use, but is an important rock-forming mineral. Nonmetallic dark color, shows cleavage on 2 planes at 56 and 124 degrees. Vitreous to dull luster, black to dark green, H=5.5 - 6, G=3.4, streak gray to brown.
Kaolinite
Aluminum silicate. Used in pottery, brick, china, and porcelain. Nonmetallic light color, does not scratch glass, no cleavage. Earthy luster, usually white, H=1.5 - 2, G=2.6, massive variety has earthy fracture, streak white, earthy odor when moist.
Magnetite
Iron oxide. Used as a source of iron. Metallic luster, streaks black. Dull to metallic luster, black color, H=5.5 - 6.5, G=5.1, fracture is rough to conchoidal, may be magnetic.
Muscovite
Potassium aluminosilicate. Used in fire retardant, paints, and lubricants. An important rock-forming mineral. Nonmetallic light color, does not scratch glass, shows basal cleavage. Vitreous to pearly luster, color is clear to silver or light brown, H=2.5, G=2.8, streak white, forms sheets.
Olivine
Iron magnesium silicate. Used in refractory bricks and is an important rock-forming mineral. Nonmetallic light color, scratches glass, no cleavage. Vitreous luster, light emerald to pale yellowish green, H=6.5 - 7, G=3.2 - 4.3, conchoidal fracture, common in granular masses, white streak.
Orthoclase
Potassium aluminosilicate. Used as a mild abrasive and is an important rock-forming mineral. Nonmetallic light color, scratches glass, shows cleavage nearly 90 degrees. Vitreous luster, white to orange or brown, H=6, G=2.6, muscle fiber appearance, streak white.
Plagioclase
Calcium or sodium aluminosilicate. Used in china and dentures. An important rock-forming mineral. Nonmetallic light color, scratches glass, shows cleavage near 90 degrees. Vitreous luster, white to gray, H=6, G=2.6, striations are diagnostic, streak white.
Pyrite
Iron sulfide. Used as a source of sulfur. Also known as fool's gold, which is used to make sulfuric acid. Metallic luster, streak greenish black. Shiny metallic luster, brassy yellow color, H=6 - 6.5, G=5.1, rough to conchoidal fracture, crystal habit may be cube, octahedron or pyritohedron.
Quartz
There are two varieties of this mineral. Silicon dioxide. Used as an aggregate-sand component, in glass, and in jewelry. Can be nonmetallic dark and light colors. Scratches glass, no cleavage. Vitreous luster, variable color (gray, brown, black; clear pink to purple), H=7, G=2.65, crystals common, conchoidal fracture, streak white.
Sphalerite
Zinc sulfide. Used as a source of zinc. Nonmetallic dark color, does not scratch glass, shows dodecahedral cleavage (6 planes). Adamantine to resinous luster, yellowish brown to black, H=3.5 - 4, G=4, streaks yellow. Smells like eggs.
Talc
Magnesium silicate. Used in paints, roofing, paper, and body powder. Nonmetallic light color, does not scratch glass, no cleavage. Pearly luster, light green, gray or white color, H=1, G=2., streak white, soapy feel.