Mineral List
Biotite Mica - Luster: NM Streak: gray-brown to white Distinctive properties: black, green-black, or brown-black; cleavage excellent; short prisms that split easily into sheets
Calcite - Luster: NM Streak: white Distinctive properties: usually colorless, white, or yellow; excellent cleavage in 3 directions not at 90
Chalcedony - Luster: NM Streak: too hard Distinctive properties: colorless, white, yellow, light brown, or other pastel colors; conchoidal fracture
Dolomite - Luster: NM Streak: white Distinctive properties: white, gray, or pink; cleavage excellent in 3 directions; breaks into rhombohedrons
Hornblende - Luster: NM Streak: white to pale gray Distinctive properties: dark gray or black; forms prisms with good cleavage at 56 and 124; brittle; splintery or asbestos forms
K-Feldspar - Luster: NM Streak: white Distinctive properties: orange, white, brown, green, or pink; cleavage excellent in 2 directions at nearly 90
Muscovite Mica - Luster: NM Streak: white Distinctive properties: colorless, yellow, brown, or red-brown; cleavage excellent in 1 direction
Pyroxene - Luster: NM Streak: white to pale gray Distinctive properties: dark green to brown or black; forms short 8 sided prisms; two good cleavage that intersect at nearly right angles
Quartz - Luster: NM greasy Streak: too hard Distinctive properties: usually colorless, white, or gray, but can occur in all colors; no cleavage |
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Minerals - Physical Properties
Crystal habit, cleavage and fracture, density, color, streak, lustre, hardness, other properties (magnetism, acid reaction, taste)
Cleavage: how a mineral brealks along planes.
Fracture: breakage without a definite shape.
Terms: conchoidal, uneven, hackly, splintery, crumbly, smooth.)
Streak: color of powdered mineral streak on unglazed porcelain. Lustre: how a mineral reflects and penetrates light. Hardness: measure of a mineral's resistance to abrasion (strength of bonds) |
Mineral Groups
Silicates
98% of crust volume by weight; 75% of earth's mass.
Examples: Quartz, feldspar, mica, amphibole, pyroxene, olivine, clay minerals
Rock-forming minerals
Felsic minerals (fel = feldspar + sic = silica) eg, Quartz, feldspar, mica
Mafic minerals (ma = magnesium + fic = iron) eg, Pyroxene |
Felsic - describing light colored minerals like feldspar, quartz, and muscovite.
Mafic - describing dark colored, ferromagnesian minerals like olivine and pyroxene
What are Minerals?
Natural, inorganic, crystalline solid
Specific internal structure, chemical composition
Composed of a geometric pattern of atoms chemically bonded into a crystalline structure |
Crystalline structure - description of the ordered arrangement of atoms, ions or molecules in a crystalline material.
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