Aurichalcite
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Aurichalcite | |
---|---|
General | |
Category | Carbonate mineral |
Chemical formula | (Zn,Cu)5(CO3)2(OH)6 |
Identification | |
Color | pale green, greenish blue, sky blue |
Crystal habit | Acicular to druzy encrustations |
Crystal system | Monoclinic-prismatic |
Cleavage | [010] Perfect |
Fracture | Uneven |
Mohs Scale hardness | 2 |
Luster | Pearly |
Refractive index | nα = 1.655 nβ = 1.740 nγ = 1.744 |
Optical Properties | Biaxial (-) |
Birefringence | 0.0890 |
Pleochroism | Weak colorless to pale green |
Streak | Light blue |
Specific gravity | 3.64 - 3.9 |
Aurichalcite is a carbonate mineral, usually found as a secondary mineral in copper and zinc deposits. Its chemical formula is (Zn,Cu)5(CO3)2(OH)6. The zinc to copper ratio is about 5:2.
Associated minerals include: rosasite, smithsonite, hemimorphite, hydrozincite, malachite and azurite.
It was first described in 1839 by Bottger who named the mineral for its zinc and copper content after the Greek όρειχαλκος, for "mountain brass" or "mountain copper", the name of a fabulous metal.