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Brochantite
Chemical Formula	Cu4SO4(OH)6
Species	Sulfates
Crystal System	Monoclinic
Mohs Scale	3-4
Specific Gravity	3.97
Color	Green, emerald green, or black
Streak	Pale green
Luster	Vitreous, Pearly
Refractive Index	n = 1.728 n = 1.771 n = 1.800
Diaphaneity	Transparent, Translucent
Cleavage	PerfectOn perfect.
Fracture	Irregular/Uneven, Conchoidal
Crystal Habit：Prismatic crystals; acicular needle-like crystals; druse
Geological Setting：In arid climates or in rapidly oxidizing copper sulfide deposits under low acid conditions.

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).

Crystals of brochantite can range from emerald green to black-green to blue-green, and can be acicular or prismatic. Brochantite is often associated with minerals such as malachite, azurite, and chrysocolla, and may form pseudomorphs with these minerals.

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