The formation and chemical characteristics of corundum by metamorphic reactions in the Chimwadzulu mine, Ntcheu District, Malawi.

Abstract

Chimwadzulu sapphire and ruby mine is located in Chimwadzulu Hill, Ncheu District from 150 km south of Lilongwe, Malawi. It is one of the oldest gemstone deposits on the African continent. The corundum is found in the amphibolite. The mechanism of corundum crystallization is unclear. In this study, we examine the mineralogical and chemical characteristics of corundum. Chemical compositions of corundum grains were determined using EPMA and LA-ICP-MS. The results show that the corundum is the metamorphic origin on the discrimination diagram utilizing trace element compositions.