Sapphire, rough and faceted, from the Rock Creek deposit in Montana has become one of the pillar gems of American origin in the global colored gemstone market. Over the past 10 years, Potentate Mining ...

This study reports on the gemological and geochemical characteristics of Sri Lankan sapphires from the secondary deposits of Balangoda and Ratnapura, as well as the results of U-Pb dating of zircon ...