gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/002646198547945 The Composition and Structure of Jeanbandyite and Natanite Betterton J. 21 Linkway, Edgcumbe Park, Crowthorne, Berkshire, RG45 6ES, UK Green D. I. Manchester Museum, The University, Manchester, MI3 9PL, UK Jewson C. Lower Carneggy Cottage, Greenbottom, Truro, Cornwall, TR4 8QL, UK Spratt J. Tandy P. Department of Mineralogy, Natural History Museum, Cromwell Road, London, SW7 5BD, UK 10 1998 62 5 707 712 23 10 1997 23 12 1997 Copyright © 1998, The Mineralogical Society 1998 Abstract

The rare iron-tin hydroxide minerals natanite and jeanbandyite occur as small pseudo-octahedral crystals in high-temperature Sn-Cu-As veins at Penberthy Croft Mine and Hingston Downs Quarry, Cornwall. The lattice parameters for jeanbandyite and natanite are reported and compared to previously calculated values. The chemical composition of jeanbandyite is discussed and a significant proportion of divalent Fe and Mn is shown to be present.

 Keywords Cornwall jeanbandyite natanite