gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1967.036.279.15 The Nature of ‘Ameletite’ Coombs D. S. Wilkinson J. F. G. Geology Department, University of Otago, Dunedin, New Zealand and Geology Department, University of New England, Armidale, New South Wales 9 1967 36 279 438 443 16 2 1967 Copyright © 1967, The Mineralogical Society 1967 Summary

Originally described in phonolitic rocks from the Dunedin district, New Zealand, ameletite was considered by Marshall (1929) to be a chlorine-bearing sodium aluminium silicate, probably a feldspathoid, and later, a zeolite of unspecified composition. Optical, X-ray, and chemical data on several ‘ameletite’-bearing felsic volcanic rocks from the type area indicate that material previously designated as ameletite is variously nepheline and mixtures of sodalite, analcime, phillipsite, and nepheline. Criteria thought to be characteristic of ameletite are discussed.