Brochantite is a sulfate , one of a number of cupric sulfates Formed in arid climates or in rapidly oxidizing copper sulfide deposits, it was named by Armand Lévy, geologist A. J. M. Brochant de Villiers
Crystals green to black-green to blue-green, and can be acicular or prismatic. Brochantite is often associated with minerals such as malachite , azurite, and may form pseudomorphs with these minerals.
The mineral is found in a number of locations around the world, notably the southwestern United States), Serifos.
Brochantite is a common corrosion product on bronze sculptures located in urban areas, where atmospheric sulfur dioxide (a common pollutant) is present. Brochantitie forms mainly in exposed areas where weathering prevents accumulation copper ions and enhancement in the acidity of water films. In sheltered areas, the main corrosion product is antlerite.