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.[1]
| Kuramite | |
|---|---|
| General | |
| Category | Sulfide |
| Formula (repeating unit) | Cu3SnS2 |
| Crystal system | Tetragonal |
| Identification | |
| Color | Grey, Steel Grey |
| Crystal habit | Inclusions, Microscopic crystals |
| Mohs scale hardness | 5 |
| Luster | Metallic |
| Streak | Metallic |
| Density | 4.56g/cm3 |
| References | [1][2][3][4] |
Occurrence
editKuramite 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.[4]
Kuramite has also been found in the Arctic Ocean, Argentina, Chile, DR Congo, Greece, Hungary, Japan, United Kingdom, and USA.[4]
Physical properties
editKuramite's hardness on the Mohs scale is 5, and it has a density of 4.56.[2] It is an opaque steel grey color with a metallic luster and a metallic streak.
Chemical properties
editThe chemical formula of Kuramite is Cu3SnS4 with common impurities being iron, zinc and indium (Fe, Zn, and In).[4][3]
| Copper | 43.56% |
| Tin | 27.13% |
| Sulfur | 29.31% |
X-ray powder pattern
editX-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).[1] 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.
| d-spacing | Intensity |
|---|---|
| 3.13 Å | (10) |
| 1.914 Å | (8) |
| 1.640 Å | (6) |
| 1.108 Å | (4) |
| 1.244 Å | (3) |
| 2.70 Å | (2) |
| 1.044 Å | (2) |
See also
editReferences
edit- ^ a b c Kovalenker, V.A., Evstigneeva,T.L., Troneva, N.V., Vyal´sov, L.N. (1979) Kuramite, Cu3SnS4, a new mineral of the stannite group. Zapiski Vsesoyuznogo Mineralogicheskogo Obshchestva: 108: 564-569.
- ^ a b John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, and Monte C. Nichols, Eds., Handbook of Mineralogy, Mineralogical Society of America, Chantilly, VA 20151-1110, USA.
- ^ a b http://www.webmineral.com/data/Kuramite.shtml (accessed December 2023)
- ^ a b c d Hudson Institute of Mineralogy, 2023, Kuramite: https://www.mindat.org/min-2291.html (accessed December 2023)