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A calcian ralstonite-like mineral from the Cleveland Mine, Tasmania, Australia

Published online by Cambridge University Press:  05 July 2018

W. D. Birch  and
A. Pring
W. D. Birch
Affiliation:
Department of Mineralogy and Petrology, Museum of Victoria, 285 Russell Street, Melbourne, Victoria, 3000
A. Pring
Affiliation:
Department of Mineralogy, South Australian Museum, North Terrace, Adelaide, South Australia, 5000
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Abstract

A calcium-rich ralstonite, forming colourless octahedral crystals up to 2 mm across, occurs in a F-rich assemblage at the Cleveland Mine, northwestern Tasmania. Other minerals present include well-crystallized morinite, gearksutite, vivianite, siderite, K-rich feldspar (adularia), fluorite and quartz. The F-rich assemblage probably formed during greisenization when Na and F-rich magmatic brines reacted with enclosing carbonate host rocks to produce hydrothermal Na-Ca-Mg-bearing solutions. Chemical analysis of the ralstonite-like mineral gave a formula (Na1.47Ca0.52)(Mg1.49Al0.55P0.04)F6 [(OH)0.43O0.36F0.21)].

This differs from the ‘pyrochlore’ formula, due to the substitution of Ca + (OH,O,F) for H2O, in addition to the coupled substitution of Na + Mg for Al in ‘normal’ ralstonites. The Cleveland Mine ralstonite has the highest recorded Ca, Na and Mg contents. While the mineral is likely to be a new species on chemical grounds, single crystal X-ray photographs indicate the structure is disordered, possibly composed of small compositional domains.

Keywords

ralstoniteCleveland MineTasmaniaAustralia
Type
Mineralogy and Petrology
Information
Mineralogical Magazine , Volume 54 , Issue 377 , December 1990 , pp. 599 - 602
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1990

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References

Cowley, J. M. and Scott, T. R. (1948) Basic fluorides of aluminium. J. Amer. Chem. Soc. 70, 105.CrossRefGoogle Scholar
Cox, R. and Glasson, K. R. (1971) Economic geology of the Cleveland Mine, Tasmania. Econ. Geol. 66, 861-78.CrossRefGoogle Scholar
Cross, W. and Hillebrand, W. F. (1883) Contributions to the mineralogy of the Rocky Mountains. II-Minerals from the neighbourhood of Pikes Peak. US Geol. Surv. Bull. 20, 40-74.Google Scholar
Jackson, P. G. (1985) Minerals of the Tin Mines. Minerals of Tasmania. Mineralogical Societies of Victoria, New South Wales and South Australia Seminar (Abstract).Google Scholar
Kwak, T. A. P. and Nicholson, M. (1988) Szaibelyite and fluoborite from the St Dizier-Sn-borate skarn deposit, NW Tasmania, Australia. Mineral. Mag. 52, 713-16.CrossRefGoogle Scholar
Pabst, A. (1939) Formula and structure of ralstonite. Amer. Mineral. 24, 566-76.Google Scholar
Pauly, H. (1965) Ralstonite from Ivigtut, South Greenland. Ibid. 50, 1851-64.Google Scholar
Raade, G. and Haug, J. (1980) Rare fluorides from a soda granite in the Oslo region, Norway. Mineral. Record, 11, 83-91.Google Scholar
Ransom, D. M. and Hunt, F. L. (1975) Cleveland Tin Mine; in Knight, C. L. (ed.), Economic Geology of Australia and Papua New Guinea. I Metals, 584-91. Australia. Inst. Mining Metall. Monogr. Ser. No. 5.Google Scholar
Ryabenko, S. V., Demina, N. P. and Naumova, I. S. (1988) New data on ralstonite. Novye Dannye o Mineralakh (Mineralogicheskii Muzei A. E. Fersmana) 35, 204-11 (In Russian, not sighted).Google Scholar
Stepanov, V. I. and Moleva, V. A. (1962) On the ralstonite from Ilmen Mountain, Central Kazakhstan and Kamchatka. Zap. Vses. Mineral. Obshch. 91, 556-72.Google Scholar
Wright, J. (1985) The occurrence of rare fluorides and phosphates at the Mt Bischoff Tin Deposit. Minerals of Tasmania. Mineralogical Societies of Victoria, New South Wales and South Australia Seminar (Abstract).Google Scholar