gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1996.060.402.07 Mineralogy Compositional Segregation and Solid Solution in the Lead-Dominant Alunite-Type Minerals from Broken Hill, N.S.W. Rattray K. J. Taylor M. R. Bevan D. J. M. Department of Chemistry , Flinders University, GPO Box 2100 Adelaide, South Australia 5000, Australia Pring A. Department of Mineralogy, South Australian Museum, North Terrace, Adelaide, South Australia 5000, Australia 10 1996 60 402 779 785 27 11 1995 8 2 1996 Copyright © 1996, The Mineralogical Society 1996 Abstract

A study of the composition and unit cell data of a suite of lead-rich minerals of the alunite-jarosite group from the oxidized zone of the ore body at Broken Hill, New South Wales, Australia, has revealed almost complete XO4 (X = As, P, S) solid solution in these minerals at this deposit. The species in the group noted are hidalgoite, hinsdalite, beudantite, segnitite and plumbogummite. These minerals at Broken Hill exhibit a number of growth textures, including oscillatory zoning, colloform banding and replacements. Zoning in these minerals is due to the segregation of Al- and Fe-rich members, and compositions indicate a strong coupling of Fe3+ with AsO43− and AI with PO43−.

 Keywords segregation solid-solution hidalgoite plumbogummite alunite-type minerals Broken Hill Australia