Russellite

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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[edit]

  1. ^ a b c d Russellite: Russellite data on Mindat.org
  2. ^ a b 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.