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Brochantite



Brochantite

General
CategorySulfate mineral
Chemical formulaCu4SO4(OH)6
Identification
ColorGreen, emerald green, or black
Crystal habitPrismatic crystals; acicular needle-like crystals; druse
Crystal systemMonoclinic
CleavagePerfect [100]
FractureConchoidal - brittle
Mohs Scale hardness3.5 - 4.0
LusterVitreous - pearly
Refractive indexnα = 1.728 nβ = 1.771 nγ = 1.800
Optical PropertiesBiaxial (-), 2V measured: 72°
Birefringenceδ = 0.072
PleochroismWeak
StreakPale green
Specific gravity3.97
DiaphaneityTransparent to translucent
References[1][2][3]

Brochantite is a sulfate mineral, one of a number of cupric sulfates. Its chemical formula is CuSO4·3Cu(OH)2. Formed in arid climates or in rapidly oxidizing copper sulfide deposits, it is named for its discoverer, the French geologist and mineralogist, A. J. M. Brochant de Villiers (1772-1840).

Additional recommended knowledge

The mineral is found in a number of locations around the world, notably the southwestern United States (especially Arizona) and Chile.

References

  1. ^ http://webmineral.com/data/Brochantite.shtml Webmineral
  2. ^ http://rruff.geo.arizona.edu/doclib/hom/brochantite.pdf Mineral Handbook
  3. ^ http://www.mindat.org/min-779.html Mindat
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Brochantite". A list of authors is available in Wikipedia.
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