Furutobeite , Quartz , Tennantite Locality: Tsumeb Mine (Tsumcorp Mine), Tsumeb , Otjikoto (Oshikoto) Region, Namibia ( Locality at mindat.org ) Size: 2.7 x 2.6 x 1.8 cm. This exceedingly rare species occurs as hackly, black crystals, to .5 cm across, associated with .5 cm in length, colorless quartz crystals. Both of these species are on earlier formed, blocky, dark gray crystals of tennantite, up to 1.0 cm across. This specimen has exceptional crystals, starkly perched on contrasting matrix because of the quartz sprays. Analyzed by Dr. Marcus Origlieri. Ex. Uli Bahmann Collection. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Furutobeite
Furutobeite is an IMA-recognized mineral species in the sulfide class, with the chemical formula (Cu,Ag)₆PbS₄.
It crystallizes in the monoclinic crystal system.
Key properties: specific gravity 6.74; Metallic luster.
IMA symbol Fur, IMA status: approved, named in 1978.
Found in veinlets of stromeyerite that cut bornite in the Kuroko zone of a stratabound, Kuroko-type, massive sulfide deposit (Furutobe mine, Japan).
It is found associated with Stromeyerite, bornite, galena, sphalerite, tennantite, digenite, argentian gold.
The name is taken from the type locality at the Furutobe mine, Japan.