Clinobisvanite, Monoclinic BiVO4, a New Mineral from Yinnietharra, Western Australia

P. J. Bridge and M. W. Pryce
Government Chemical Laboratories, Perth, Western Australia

Summary: Monoclinic BiVO4, well known as a high-temperature compound, has been found as a mineral at Yinnietharra and subsequently in specimens from five further W.A. localities, Londonderry, Wodgina, Menzies, Westonia, and Corinthia. At the type locality, the mineral occurs on garnet in a beryl-bearing spessartine pegmatite associated with bismutite, bismutoferrite, and other pegmatite minerals.

Clinobisvanite occurs as yellow powder and orange aggregates and plates to 0·1 mm, is commonly intergrown with bismutite, and frequently associated with its polymorph pucherite. It has a yellow streak, earthy to subvitreous lustre, is very soft with perfect {010} cleavage, D calc. 6·95, transparent in very thin cleavage flakes, and shows multiple twinning with cross hatching, strong dispersion and n calc. 2·63.

Space group I 2/a, a, 5·186, b 11·708, c 5·100 Å, β 90° 26′ refined from powder data. An electronprobe analysis gave Bi2O3 69·88, V2O5 27·63, PbO 1·34 sum 98·85. Cell content 4[BiVO4] with minor substitution of Pb for Bi. All measurable data agree with earlier work including a prior description of the mineral from Mozambique.

Type material is preserved in the government collections at the Government Chemical Laboratories, W.A.

Mineralogical Magazine; December 1974 v. 39; no. 308; p. 847-849; DOI: 10.1180/minmag.1974.039.308.03
© 1974, The Mineralogical Society
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