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www.mineralgallery.co.za Minerals A-E |
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Brochantite |
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Name
Brochantite
Chemistry
Cu4(SO4)(OH)6
Uses
Sometimes as a precious stone
Color-
Emerald green, black-green.
Hardness
3.5-4
Specific gravity
3.97
Crystal system:
Monoclinic crystal form: prism. The habit is usually stout prismatic crystals but it also forms tabular crystals parallel to the base. The crystals from the Congo forms as loose agregates of acicular crystals. It also forms massive or granular crusts.
Accompanied by:
Linerite, azurite, antlerite, malachite,
Fracture
Uneven to conchoidal fracture.
Luster
Vitreous, pearly.
Cleavage
Good on (100)
Streak
Light green
Similar to:
Antlerite, Malachite
Brochantite is a secondary mineral found in the oxidized zone of copper deposits especially in arid regions. It occurs worldwide. You recognise it by it's color and habit as well as the associations. It is soluble in hydrochloric and nitric acid. Crystals up to 70 mm long are found in Bisbee, together with pseudo-morphs of malachite after brochantite. Tsumeb was also known for Brochantite and the DRC has some fine crystals. At CerroVerde in Peru one finds emerald green crystals up to 50 mm long.
