Musgravites from Sri Lanka

摘要

Physical and chemical properties of four transparent, gem-quality musgravites from Sri Lanka are presented. These are the first data for samples of this rare mineral species originating from the numerous secondary deposits of this island. The musgravites were identified by Raman spectroscopy and electron microprobe analysis. Physical data such as refractive indices and densities are related with transition metal contents, especially with iron and zinc values. Mineral and multiphase inclusions indicate a formation of our samples in different environments. A musgravite crystal containing spinel exsolution lamellae is possibly formed in high grade metamorphic rocks, two samples with graphite and magnesite inclusions possibly originate from magnesian skarns.