gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/002646198547765 Tamarugite on the Isle of Wight, UK King R. J. The Oak, Longdon, Gloucestershire GL20 6AR, UK 6 1998 62 3 371 372 11 8 1997 25 9 1997 Copyright © 1998, The Mineralogical Society 1998 Abstract

Tamarugite (NaAl(SO4)2·6H2O) occurs at Compton Chine (NGR SZ 36808513), on the Isle of Wight, U.K., as globular encrustations covering an area of 2.8 m2 on argillaceous pyritous siltstones of the Lower Greensand Group, Lower Cretaceous. It is proposed that the production of H2SO4 from oxidizing pyrite in the siltstones releases Al ions from the argillaceous sediments, the Na content being acquired from sea spray. An analogy is made between Compton Chine and an occurrence in Victoria, Australia.

 Keywords tamarugite Lower Greensand Group sulphate Isle of Wight