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Tungusite: new data, relationship with gyrolite and structural model

Published online by Cambridge University Press:  05 July 2018

Giovanni Ferraris
Affiliation:
Dip. Scienze Mineralogiche e Petrologiche, Univ. Torino, Via Valperga Caluso 37, 10125 Torino, Italy
Alessandro Pavese
Affiliation:
Dip. Scienze della Terra, Sez. Mineralogia, Univ. Milano, Via Botticelli 23, 20133 Milano, Italy
Svetlana V. Soboleva
Affiliation:
Inst. Ore Deposits, Petrography, Mineralogy and Geochemistry, Russian Acad. Sci., Staromonetny per. 35, Moscow, Russia

Abstract

New chemical analyses, electron and X-ray powder diffraction data, and comparison with gyrolite and reyerite show that tungusite has the ideal formula , symmetry P and a = 9.714(9), b = 9.721(9), c = 22.09(3), α = 90.13(1)°, β = 98.3(2)°, γ = 120.0(1)°, Z = 1. A structural model for tungusite is derived by splitting the double tetrahedral layer of reyerite and inserting a trioctahedral X sheet which is ideally occupied by Fe2+. Polytypism phenomena due to different relative positions between tetrahedral and X sheets are discussed. A substitutional solid solution represented by the formula [Ca14(OH)8]Si24−yAlyO60[NaxM9−(x+z)z(OH)14−(x+y+2z)·(x+y+2z)H2O] includes tungusite (x = y = z = 0, M = Fe2+ and gyrolite (x = 1, y = 1, z = 6, M = Ca).

Type
Mineralogy
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1995

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References

Anastasenko, G. F. (1978) Boron-bearing traps of the North-West Siberian platform. Leningrad Univ. Press, Leningrad (in Russian).Google Scholar
Duncumb, P. and Reed, S.J.B. (1968) The calculation of stopping power and back-scattered effects in electron probe analysis. In: Quantitative electron probe microanalysis (Heinrich, K.F.J., ed.) NBS spec. pub. 298.Google Scholar
Garavelli, C.L. and Vurro, F. (1984) Rend. Soc. Ital. Mineral. Petr., 39, 695–704.Google Scholar
Kudriashova, V.I. (1966) Dokl. Akad. Nauk SSSR, 171, 1167-70. [Mineral. Abstr. XVIII, 206] (in Russian).Google Scholar
Merlino, S. (1988a) Mineral. Mag., 52, 247–55.CrossRefGoogle Scholar
Merlino, S. (1988*) Mineral. Mag., 52, 377–87.CrossRefGoogle Scholar
Meyer, J.W. and Jaunarajs, J.L. (1961) Amer. Mineral., 46, 913–33.Google Scholar
Reverdato, V.V., Pertzev, N.N. and Korolyuk, V.N. (1979) Contrib. Mineral. Petrol, 70, 203–8.CrossRefGoogle Scholar
Vainshtein, B.K. (1964) Structure Analysis by Electron Diffraction. Pergamon Press, Oxford.Google Scholar
Zvyagin, B.B, (1967) Electron Diffraction Analysis of Clay Mineral Structures. Plenum Press, New York.CrossRefGoogle Scholar

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