Russellite

For the Irish political faction, see Russellite Unionist. For the religious group, see Charles Taze Russell and Bible Student movement.
Russellite
General
Category Tungstate minerals
Formula
(repeating unit)		 Bi2WO6
Strunz classification 04.DE.15
Crystal symmetry Orthorhombic mm2
Unit cell a = 5.43 Å, b = 16.43 Å, c = 5.45 Å; Z = 4
Identification
Color Yellow-green, yellow
Crystal habit Fine-grained, compact, massive
Crystal system Orthorhombic
Mohs scale hardness 3.5
Specific gravity 7.33 - 7.37
Optical properties Biaxial (+)
Refractive index 2.17 - 2.51
Dispersion relatively strong
References [1][2][3]

Russellite is a bismuth tungstate mineral with the chemical formula Bi2WO6.[1] It crystallizes in the orthorhombic crystal system. Russellite is yellow or yellow-green in color, with a Mohs hardness of 3½.[1]

Russellite is named for the mineralogist Sir Arthur Russell, and the type locality is the Castle-an-Dinas Mine,[1] near St Columb Major in Cornwall, where it was found in 1938 in wolframite.[4] It occurs as a secondary alteration of other bismuth bearing minerals in tin - tungsten hydrothermal ore deposits, pegmatites and greisens. It typically occurs associated with native bismuth, bismuthinite, bismite, wolframite, ferberite, scheelite, ferritungstite, anthoinite, mpororoite, koechlinite, cassiterite, topaz, muscovite, tourmaline and quartz.[2]


References

  1. ↑ 1.0 1.1 1.2 1.3 Russellite: Russellite data on Mindat.org
  2. ↑ 2.0 2.1 Handbook of Mineralogy
  3. ↑ Webmineral data
  4. ↑ Embrey, P. G.; Symes, R. F. (1987). "The Mines and Mining". Minerals of Cornwall and Devon. London: British Museum (Natural History). p. 54. ISBN 0-565-00989-3.