gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1988.052.366.05 Mineralogy and Crystal Structures Vanadium-Bearing Margarite from the Lachlan Fold Belt, New South Wales, Australia Morand V. J. * Department of Geology and Geophysics, University of Sydney, N.S.W., Australia, 2006

Present address: Department of Earth Sciences, Monash University, Clayton, Victoria, Australia, 3168.

 6 1988 52 366 341 345 9 9 1986 1 6 1987 Copyright © 1988, The Mineralogical Society 1988 Abstract

Margarite occurs in Ordovician black slate within the contact aureole of the Wyangala Batholith, in the Lachlan Fold Belt in New South Wales. This occurrence is the first described from New South Wales. It is a regional metamorphic mineral replacing chiastolitic andalusite, and contains up to 1.07% V2O3 and up to 0.37% Cr2O3. Vanadium and chromium here substitute for octahedral aluminium. Margarite is produced by a local reaction in which Ca and H2O are introduced into andalusite grains. There is a significant paragonite component in the margarite but negligible muscovite solid solution.