Tsumcorite Locality: Tsumeb Mine (Tsumcorp Mine), Tsumeb , Otjikoto (Oshikoto) Region, Namibia ( Locality at mindat.org ) Size: 3.7 x 2.9 x 1.8 cm. Freestanding crystals of tsumcorite in relatively large clusters to several mm. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Tsumcorite
A yellow-brown hydrated lead-iron-zinc arsenate named for the TSUMeb CORporation's Tsumeb mine.
Intro adapted from Wikipedia (CC BY-SA).
Tsumcorite is an IMA-recognized mineral species in the arsenate class, with the chemical formula PbZn₂(AsO₄)₂·2H₂O.
It crystallizes in the monoclinic crystal system (space group C2/m). It is a member of the Natrochalcite structural group.
Key properties: Mohs hardness 4.5; specific gravity 5.2; Yellow streak; Vitreous luster; refractive index 1.914; optically biaxial.
IMA symbol Tmc, IMA status: approved, named in 1969.
A rare secondary mineral found in the oxidized zone of some arsenic-bearing hydrothermal Pb–Zn deposits.
It is found associated with Willemite, smithsonite, mimetite, scorodite, anglesite, arseniosiderite, beaverite, beudantite, carminite, ludlockite, o’danielite, zincroselite, stranskiite.
In recognition of the TSUMeb CORporation’s support of mineralogical investigations of the Tsumeb, Namibia orebody.