The blue sapphire deposit found in Rwanda especially in Nyamasheke and Rusizi Districts comes from alkali basaltic rocks and is alluvial type. The deposit is potentially of economic importance, and has been mined in the past by artisanal miners. Today, with the new mining strategy it is envisaged to modernize the mining method by using updated technology and mechanical means and adding value by processing locally.
The region of Nyamasheke District is located in the Western Province of Rwanda. It borders Rusizi District in the South, and both are part of former Province of Cyangugu bordering the Democratic republic of Congo in the West. The geology of these districts is related to volcanic rocks appropriate to sapphire mineralization.
Currently, this mineral is under prospection by Ngali Mining Ltd.