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Duftite is a relatively common arsenate mineral with the formula CuPb(AsO4)(OH), related to conichalcite. It is green and often forms botryoidal aggregates. It is a member of the Adelite-Descloizite Group, Conichalcite-Duftite Series. Duftite and conichalcite specimens from Tsumeb are commonly zoned in colour and composition. Microprobe analyses and X-ray powder-diffraction studies indicate extensive substitution of Zn for Cu, and Ca for Pb in the duftite structure. This indicates a solid solution among conichalcite, CaCu(AsO4 )(OH), austinite, CaZn(AsO4)(OH) and duftite PbCu(AsO4)(OH), all of them belonging to the adelite group of arsenates.[5] It was named after Mining Councilor G Duft, Director of the Otavi Mine and Railroad Company, Tsumeb, Namibia.[1] The [[Type locality (geology)|type locality is the Tsumeb Mine, Tsumeb, Otjikoto Region, Namibia. Structure The structure[6] is composed of chains of edge-sharing CuO6 distorted octahedra parallel to the c axis. The chains are linked by AsO4 tetrahedra and Pb atoms. Environment Duftite is an uncommon product of weathered sulfide ore deposits. It is associated with azurite at the type locality[1], and with bayldonite, segnitite, agardite and gartrellite at the Central Cobar Mines, New South Wales, Australia, where some pseudomorphs of duftite after mimetite have also found.[7] It occurs in association with olivenite, mottramite, azurite, malachite, wulfenite and calcite in the Tsumeb, Namibia deposite. It occurs with bayldonite, beudantite, mimetite and cerussite in the Cap Garonne mine, France.[4] Distribution Reported from Argentina, Australia, Austria, Chile, the Czech Republic, France, Germany, Greece, Italy, Japan, Mexico, Namibia, Poland, Portugal, Russia, South Africa, Spain, Switzerland, the UK, the USA and Zimbabwe.[3] References 1. ^ a b c Wherry E T and Foshag W F (1921). New mineral names. American Mineralogist 6: 140 to 141
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