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Wesselsite, SrCu[Si4O10], a further new gillespite-group mineral from the Kalahari Manganese Field, South Africa

Published online by Cambridge University Press:  05 July 2018

G. Giester  and
B. Rieck
G. Giester
Affiliation:
Institut für Mineralogie und Kristallographie, Geozentrum, Universität Wien, Althanstr. 14, A-1090 Wien, Austria
B. Rieck
Affiliation:
Institut für Mineralogie und Kristallographie, Geozentrum, Universität Wien, Althanstr. 14, A-1090 Wien, Austria
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Abstract

Wesselsite, SrCu[Si4O10], is a new mineral species from the Wessels mine, Kalahari Manganese Field, South Africa, and it belongs to the gillespite group. Wesselsite is tetragonal, space group P4/ncc; the unit cell parameters, refined from Gandolfi film data, are a = 7.366(1), c = 15.574(3) Å V = 845.01 Å3. The strongest lines are (dobs/lobs/hkl) (7.79/35/002), (4.33/20/112), (3.89/20/004), (3.44/40/104), (3.33/100/202), (3.12/55/114), (3.03/50/212), (2.68/25/204), (2.61/30/220) and (2.32/30/116). Wesselsite is associated with hennomartinite, embedded in a matrix of sugilite, xonotlite, quartz and pectolite. Microprobe analyses of 111 samples show that it is the end-member of a solid solution series with effenbergerite, BaCu[Si4O10], with substitutions of Sr by Ba up to 50 mol.%. Wesselsite forms tiny subhedral plates in sizes not exceeding 50 × 50 × 5 µm, arranged in clusters of up to 200 µm. It shows a perfect cleavage parallel to {001}, has blue colour, white to light blue streak, and is uniaxial negative with ω = 1.630(2), ε = 1.590(5), strongly pleochroic from blue (ω) to pale blue (ε). The calculated density is 3.32 g cm−3, the measured density is 3.2(1) g cm−3.

Keywords

wesselsitestrontium copper silicategillespite groupeffenbergeritenew mineralKalahari Manganese FieldSouth Africa
Type
Mineralogy
Information
Mineralogical Magazine , Volume 60 , Issue 402 , October 1996 , pp. 795 - 798
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1996

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References

Belsky, H.L., Rossman, G.R., Prewitt, C.T. and Gasparik, T. (1984) Crystal structure and optical spectroscopy (300 to 2200 nm) of CaCrSi4OiO. Amer. Minerals, 69, 771–6.Google Scholar
Chakoumakos, B.C., Fernandez-Baca, J.A. and Boatner, L.A. (1993) Refinement of the Structures of the Layer Silicates MCuSi4O10 (M-Ca,Sr,Ba) by Rietveld Analysis of Neutron Powder Diffraction Data. J. Solid State Chem., 103, 105—13.CrossRefGoogle Scholar
Dixon, R.D. (1985) Sugilite and associated minerals from the Wessels mine, Kalahari Manganese field. Trans. Geol. Soc. South Africa, 88, 11–7.Google Scholar
Dixon, R.D. (1986) Metamorphism in the Kalahari Manganese field. Geocongress'86 Extended Abstracts Geol. Soc. South Africa, 505—8.Google Scholar
Dixon, R.D. (1989) Sugilite and associated metamorphic silicate minerals from Wessels mine, Kalahari Manganese field. Bull. Geol. Survey, South Africa, 93, 1–47.Google Scholar
Giester, G. and Rieck, B. (1994) Effenbergerite, BaCu[Si4OiO], a new mineral from the Kalahari Manganese Field, South Africa: description and crystal chemistry. Mineral. Mag., 58, 663–70.CrossRefGoogle Scholar
Hazen, R.M. and Burnham, C.W. (1974) The crystal structures of gillespite I and gillespite II: a structure determination at high pressure. Amer. Mineral, 59, 1166–76.Google Scholar
Hazen, R.M. and Finger, L.W. (1983) High-pressure and high-temperature crystallographic study of the gillespite I—II phase transition. Amer. Mineral, 68, 595–603.Google Scholar
Janczak, J. and Kubiak, R. (1992) Refinement of the Structure of Barium Copper Silicate BaCu[Si4OiO] a. 300K. Acta Crystallographica C48, 1299—301.Google Scholar
Kleyenstuber, A.S.E. (1984) The mineralogy of the manganese bearing Hotazel formation of the Proterozoic Transvaal sequence of Griqualand West, South Africa. Trans. Geol. Soc. South Africa, 87, 267–75.Google Scholar
Lin, H.C., Liao, F.L. and Wang, S.L. (1992) Structure of BaCuSi4OiO. Acta Crystallographica C48, 1297—9.Google Scholar
Mandarino, J.A. (1981) The Gladstone-Dale relationship: Part IV. The compatibility concept and its application. Canad. Mineral, 70, 441–50.Google Scholar
Mighell, A.D., Hubbard, C.R. and Stalick, J.K. (1981) NBS * AIDS83. A FORTRAN Program for crystallographic Data Evaluation NBS Technical Note 1141.Google Scholar
Miletich, R. and Allan, D.R. (1996) The gillespite-type Cr2+ silicates BaCrSi4OJO and SrCrSi4O10. Z. Kristallogr., SuppL Issue no 11, p. 88.Google Scholar
Pabst, A. (1959) Structures of some tetragonal sheet silicates. Acta Crystallographica, 12, 733–9.CrossRefGoogle Scholar
Von Bezing, K.L., Dixon, R.D., Pohl, D. and Cavallo, G. (1991) The Kalahari Manganese field, an update. Mineral. Record, 22, 279–97.Google Scholar
Yvon, K., Jeitschko, W. and Parthe, E. (1977) Lazy Pulverix, a computer program for calculating X-ray and neutron diffraction powder patterns. J. Applied Crystallography, 10, 73–4.CrossRefGoogle Scholar