Malayaite and Tin-Bearing Garnet from a Skarn Gumble, NSW, Australia

I. R. Mulholland^*

Department of Geology and Geophysics, University of Sydney, Sydney, NSW 2006, Australia

^*Now at: Esso Australia Ltd., Minerals Department, 127 Kent Street, Sydney, NSW 2000, Australia.

Abstract: Malayaite and tin-bearing garnet occur within a skarn assemblage at Gumble, NSW. A metasomatic origin is proposed for these minerals under conditions of T = 300-500°C X_co2 < 0.30 and f_O₂ = 10⁻¹⁸ to 10⁻³⁰ bars. Malayaite has formed as a result of reaction between a metasomatic fluid rich in Sn, F, H₂O and silica, and tin-bearing andradite and wollastonite. The main requirements for tin-bearing skarn formation appear to be an F-Sn-rich granite, an iron-rich skarn assemblage, and a relatively long cooling history.

Mineralogical Magazine; March 1984 v. 48; no. 346; p. 27-30; DOI: 10.1180/minmag.1984.048.346.04
© 1984, The Mineralogical Society
Mineralogical Society (www.minersoc.org)