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Metamunirite, a new anhydrous sodium metavanadate from San Miguel County, Colorado

Published online by Cambridge University Press:  05 July 2018

Howard T. Evans Jr.*
Affiliation:
U.S. Geological Survey, Reston, Virginia 22092, U.S.A.

Abstract

Metamunirite, β-NaVO3, is found in cavities in sandstone in San Miguel County, Colorado, occurring as fine, fibrous, colourless needles. X-ray powder and precession photographs show the crystals to be orthorhombic, space group Pnma, with a = 14.134(7), b = 3.648(2), c = 5.357(2) Å. They are optically biaxial positive with nα = 1.780(2) (‖c), nβ = 1.800(2) (‖a), nγ ≫ 185 (‖b, fibre axis; positive elongation), 2Vz moderate. A crystal structure analysis, confirming the previously determined structure of β-NaVO3, shows the presence of (VO3)n chains made up of zig-zag VO5 square pyramids. Metamunirite is probably formed by dehydration of munirite, NaVO3.2H2O.

Type
Mineralogy
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1991

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References

Björnberg, A. and Hedman, B. (1977) The crystal structure of NaVO3.1.89H2O. Acta Chem. Scand., A31, 579-84.CrossRefGoogle Scholar
Butt, K. A. and Mahmood, K. (1983) Munirite, naturally occurring sodium vanadium oxide hydrate, a new mineral. Mineral. Mag., 47, 391–2.CrossRefGoogle Scholar
Evans, H. T., Jr. (1988) The crystallography of munirite, NaVO3.(2-x)H2O. Ibid. 52, 716-7.CrossRefGoogle Scholar
Feigelson, R. S., Martin, C. W., and Johnson, B. C. (1972) Crystal growth and properties of some alkali metal metavanadates. J. Cryst. Growth, 13/14, 686-92.CrossRefGoogle Scholar
Hanawalt, J. D., Rinn, H. W., and Frevel, L. W. (1938) Chemical analysis by x-ray diffraction. Classification and use of x-ray diffraction patterns. Indust. Eng. Chem. Anal. Ed., 10, 457512.CrossRefGoogle Scholar
Kato, K. and Takayama, E. (1984) Das Entwässerung-serhalten des Natriummetavanadats und die Kristall-struktur des Natriummetavanadats. Ada Cryst., B40, 102-5.Google Scholar
Lukács, I. and Strusievici, C. (1962) Über die Polymorphie von Natriummetavanadate. Zeit. anorg. allgem. Chem., 315, 323–6.CrossRefGoogle Scholar
Mandarino, J. A. (1976) The Gladstone-Dale relationship—Part I: Derivation of new constants. Canad. Min., 14, 498502.Google Scholar
Morris, M., McMurdie, H. F., Evans, E. H., Paretzkin, B., Parker, H. S., Panagiotopoulos, N. C., and Hubbard, C. R. (1981) Standard x-ray diffraction powder patterns. Nat. Bur. Stand. Monog. 25, Sect. 18, 68.Google Scholar
Perraud, J. (1974) Etudes sur la cristallisation de quelques metavanadates alcalins, simples ou doubles, Na+, K+, et Cs+. Rev. Chim. min., 11, 302–26.Google Scholar