New Data on Painite


James E. Shigley
Research Department, Gemological Institute of America
Stewart Street, Santa Monica, CA, 90404, USA

Anthony R. Kampf
Mineralogy Section, Natural History Museum of Los Angeles County
900 Exposition Blvd, Los Angeles, CA  90007, USA

George R. Rossman
Division of Geological and Planetary Sciences
California Institute of Technology, Pasadena, CA  91125, USA

Abstract

 A crystal of painite discovered in 1979 in a parcel of rough gem spinel from Burma represents the third known crystal of the species. This crystal is similar to the type crystal in most respects. Chemical analyses of both the new crystal antd the type crystal confirmed the essential constituents reported by Moore and Araki (1976) and showed in addition the presence of trace amounts of Fe, Cr, V, Ti, Na, and Hf. Optical absorption spectra suggest that the red colour of painite is caused principally by Cr3+ and V3+.