Kuramite
General
CategorySulfide
Formula
(repeating unit)		Cu3SnS2
Crystal systemTetragonal
Identification
ColorGrey, Steel Grey
Crystal habitInclusions, Microscopic crystals
Mohs scale hardness5
LusterMetallic
StreakMetallic
Density4.56g/cm3
References[1][2][3][4]

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]

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.[4]

Kuramite has also been found in the Arctic Ocean, Argentina, Chile, DR Congo, Greece, Hungary, Japan, United Kingdom, and USA.[4]

Physical properties

Kuramite'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

The chemical formula of Kuramite is Cu3SnS4 with common impurities being iron, zinc and indium (Fe, Zn, and In).[4][3]

Composition
Copper 43.56%
Tin 27.13%
Sulfur 29.31%

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).[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.

Powder diffraction data
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

References

  1. 1 2 3 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.
  2. 1 2 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.
  3. 1 2 http://www.webmineral.com/data/Kuramite.shtml (accessed December 2023)
  4. 1 2 3 4 Hudson Institute of Mineralogy, 2023, Kuramite: https://www.mindat.org/min-2291.html (accessed December 2023)
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