Kuramite

Kuramite is a mineral of the stannite group. It is named after the Kochbulak Au-Ag-Te deposit locality in the Chatkal-Kuraminskii Mountains in Uzbekistan, where it was first discovered.

Occurrence
Kuramite occurs in gold-sulfide-quartz veins as inclusions in goldfieldite, as observed in the Kochbulak deposit in Uzbekistan. It may also occur as microscopic crystals.

Kuramite has also been found in the Arctic Ocean, Argentina, Chile, DR Congo, Greece, Hungary, Japan, United Kingdom, and USA.

Physical properties
Kuramite's hardness on the Mohs scale is 5, and it has a density of 4.56. It is an opaque steel grey color with a metallic luster and a metallic streak.

Chemical properties
The chemical formula of Kuramite is Cu3SnS4 with common impurities being iron, zinc and indium (Fe, Zn, and In).

X-ray powder pattern
X-ray study of Kuramite was done using the powder method, in the mineralogical laboratory of IGEM, Academy of Sciences of the USSR, by G. V. Vasova (RKO-57.3, unfiltered FeK). Kuramite was found to relate to the stannite-kesterite group. The parameters of the unit cell are found to be a=5.445±0.005 Å, c=10.75±0.02 Å, c/a=1.972.