Tin-Bearing Sulphides from St Michael's Mount and Cligga Head, Cornwall

F. Moore* and R. A. Howie
Department of Geology, King’s College London, Strand, London WC2R 2LS
*Present address: Department of Geology, College of Arts and Sciences, Shiraz University, Shiraz, Iran.

Abstract: The result of electron probe microanalyses, along with X-ray and optical data obtained for tin sulphides from two different localities in south-west England indicate that the mineral hitherto described from St Michael’s Mount as stannite is in fact kesterite, Cu2(Fe0.23Zn0.77)SnS4. The yellow ‘stannite’ reported from this locality proved to be stannoidite, Cu8(Fe2.39 Zn0.61)SnS2S12. Kesterite, Cu2(Fe0.09Zn0.90SnS4, and zincian stannite, Cu2(Fe0.63Zn0.38)SnS4, are also reported from Cligga Head. It is suggested that a more cautious approach should be taken in identifying these tin sulphides solely on their optical properties.

Mineralogical Magazine; September 1984 v. 48; no. 348; p. 389-396; DOI: 10.1180/minmag.1984.048.348.09
© 1984, The Mineralogical Society
Mineralogical Society (www.minersoc.org)