Tsumcorite is a lemon yellow, yellow-brown to red brown lead zinc iron arsenate hydrate found as spherulitic crusts, intergrown sub-parallel crystals and rarely as isolated crystals. It is a member of the Tsumcorite Group and is conspicuously named after the mining company/locality: Tsumeb Corporation/Tsumeb mine, Tsumeb, Otjikoto Region, Namibia, where it occurs with cerussite, wulfenite, smithsonite, and quartz. US localities include: the Richmond-Sitting Bull mine, Galena, Lawrence Co., South Dakota; Mammoth and Centennial Eureka mines, Tintic district, Juab Co., Utah; San Rafael mine, Lodi district, Nye Co., and Silver Coin mine, Iron Point district, Humboldt Co., Nevada. At the Ojuela mine, Mapimi, Durango, Mexico; Lavrion district mines, Attiki Prefecture, Greece; Bakara mine, Vratsa Oblast, Bulgaria; and several localities in Germany and Australia.
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