General Information:
Chemical Formula:
Cu4(SO4)(OH)6
Composition:
(Molecular Weight = 452.29 gm)
Copper 56.20 % Cu
Hydrogen 1.34 % H
Sulfur 7.09 % S
Oxygen 35.37 % O
Empirical Formula:
Cu4(SO4)(OH)6
Environment:
Secondary, formed in arid climates or in rapidly oxidizing copper sulfide deposits.
IMA Status:
Accepted IMA 1965
Locality:
Chuquicamata, Chile.
Name Origin:
Named after the French geologist and mineralogist, A. J. M. Brochant de Villiers (1772-1840).
Physical Properties:
Cleavage:
[100] Perfect
Color:
green, emerald green, or black.
Density:
3.97
Diaphaniety:
Transparent to translucent
Habits:
Acicular - Occurs as needle-like crystals., Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline)., Druse - Crystal growth in a cavity which results in numerous crystal ti pped surfaces.
Hardness:
3.5-4 - Copper Penny-Flourite
Luminescence:
None.
Luster:
Vitreous - Pearly
Streak:
pale green
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