Schneiderhohnite is a rare ferric-ferrous iron arsenate named after Hans Schneiderhohn, professor of mineralogy, University of Freiburg in Breisgau, Germany. It forms black to black-brown, sub-translucent to nearly opaque, vitreous to sub-metallic, triclinic crystals. Tsumeb produced best-of-species crystals to 2.5cm. It is found in the deep oxidation zone at Tsumeb, Namibia associated with chalcocite and zincian stottite. Schneiderhohnite also forms as an alteration product of As-bearing ores and is associated with karibibite and scorodite at the Urucum mine (Brazil), Veta Negra (Chile) and White Elephant mine (South Dakota, USA). The type locality is the Tsumeb mine, Tsumeb, Otjikoto Region, Namibia. Schneiderhohnite has subsequently been found at the Veta Negra mine, Pampa Larga district, Copiapo Province, Atacama Region, Chile; Urucum mine, Sapucaia do Norte, Galileia, Doce Valley, Minas Gerais, Brazil; White Elephant pegmatite, near Pringle, Custer Co., South Dakota, USA; and at several occurrences in the Bou-Azer district, Tazenakht, Ouarzazate Province, Souss-Massa-Draa Region, Morocco.
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