Natural-color purple diamonds from Siberia

Abstract

Twelve natural-color purple diamond crystals from Siberia, and seven round brilliants that were faceted from some of these crystals, were studied using spectroscopic methods to better understand their color and its causes. Aspects of their color and the various structural defects in these purple diamonds are due to their post-growth plastic deformation in the earth. All the samples exhibited prominent parallel planar lamellae along which the purple color was concentrated. © 2008 Gemological Institute of America.