Brochantite
Image: Robert M. Lavinsky (CC BY-SA 3.0)
Mineral NameBrochantite
Chemical FormulaCu₄(SO₄)(OH)₆
Mohs Hardness3.5
Crystal Systemmonoclinic
Lustervitreous
Streak Colorpale green
Cleavageperfect on {100}
Fractureconchoidal to uneven
Specific Gravity3.97
Colorsemerald green, dark green, bluish-green
Transparencytransparent to translucent
Type LocalityBingham, Hansonburg District, Socorro County, New Mexico, USA
Mineral Groupsulfates
Usescollector, minor copper ore
Associated Mineralsazurite, malachite, chrysocolla, native copper, cuprite, tenorite, gypsum
Rarityuncommon
Description
This specimen features a vibrant cluster of emerald green to dark green acicular (needle-like) brochantite crystals, often forming radiating aggregates or a drusy coating on a matrix.
Geological Context
Brochantite is a secondary copper sulfate mineral that forms in the oxidized zones of copper sulfide deposits, particularly in arid or semi-arid climates. It results from the alteration of primary copper minerals.
