Micas are a group of aluminosilicate minerals with a layered structure and having the general formula Na2(Al, Mg, Fe, Li)3 [AlSi3O10](OH, F)2. Mica is one of the most common rock-forming minerals in intrusive, metamorphic, and sedimentary rocks.
You can see mica stone for sale and buy it in the Minerals of Russia online store.
General | |
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Category | Phyllosilicates |
Formula (repeating unit) |
AB2–3(X, Si)4O10(O, F, OH)2 |
IMA symbol | Mca |
Identification | |
Color | purple, rosy, silver, gray (lepidolite); dark green, brown, black (biotite); yellowish-brown, green-white (phlogopite); colorless, transparent (muscovite) |
Cleavage | Almost perfect |
Fracture | flaky |
Mohs scale hardness | 2.5–4 (lepidolite); 2.5–3 biotite; 2.5–3 phlogopite; 2–2.5 muscovite |
Luster | pearly, vitreous |
Streak | White, colorless |
Specific gravity | 2.8–3.0 |
Diagnostic features | cleavage |