The Mineral brochantite
Brochantite always occurs in an intensely deep green color. It is almost exclusively in groups of small radiating needles, and often found together with the similar mineral Cyanotrichite, which has a deep blue color. The combination of bright green Brochantite and bright blue Cyanotrichite creates a beautiful and contrasting specimen when found together.
Brochantite was named in honor of French mineralogist
André-Jean-François-Marie Brochant de Villiers (1772-1840). Brochant de Villiers was a professor of geology and mineralogy in the École des Mines in France, as well as its first pupil.
Bright green to dark green
3.5 - 4
Transparent to opaque
Vitreous to silky
1,1 - pinacoidal
Conchoidal, uneven, splintery
Very rarely in visible crystals, which are prismatic and tabular. Most often acicular, radiating, earthy, grainy, encrusting, as fibrous masses, as dense bundles of acicular crystals, and as cotton-like, radiating masses. Sometimes as tiny twinned crystals that appear orthorhombic with rounded corners. Occasionally forms a pseudomorph after Azurite and Malachite, assume the crystal shape of those minerals.
Brochantite is a minor ore of copper.
Fine African localities of Brochantite include Katanga (Shaba), Congo (Zaire); Tsumeb, Namibia; and Goulmina, Mujuram, and Touissit, Morocco. Other Worldwide occurrences are Cloncurry, Mt Isa, Queensland, Australia; the Chengmenshan Mine, Jiurui, Jiangxi Province, China; and Copiapo and Chuquicamata, in the Atacama Desert, Chile. In Mexico, Brochantite comes from the Ojuela Mine, Mapimi, Durango; and a relatively new find of some of the finest examples of this mineral is the Milpillas Mine, Sonora.
Excellent Brochantite specimens have also come from many areas in the southwestern U.S. Arizona localities are Bisbee, Cochise Co.; Clifton and Morenci, Greenlee Co.; and the Grandview Mine, Concino Co. Other Southwest occurrences are Bingham, Socorro Co., New Mexico; the Douglas Hill Mine, Artesia Lake, Lyon Co., Nevada; the Tintic District, Juab Co., Utah; and the Green Monster mine, Independence, and Cerro Gordo, Inyo Co., California.
Distingushing Similar Minerals
Malachite - Effervesces in hydrochloric acid; otherwise practically indistinguishable from Brochantite.
Antlerite - Virtually indistinguishable from Brochantite without complex tests.
Dioptase - Crystals are not elongated like Brochantite.