Genesis of chrysoberyl in the pegmatites of southern Kerala, India

Abstract

Abstract In southern Kerala, India, chrysoberyl occurs in granitic pegmatites in association with quartz in alkali feldspar and is thought to crystallize earlier than beryl and sillimanite. The pegmatites are thought to have derived from the residual melts of granitic liquids formed by partial melting of the khondalites. In the absence of pyrometasomatic, desilication or aluminium-contamination processes, the genesis of chrysoberyl is explained by the CO 2 activity in residual melts. This model is at variance with the known concepts and may also explain the genesis of chrysoberyl in Sri Lanka where it is still controversial.