Coltan (Tantalium)
Short for columbite-tantalite and known industrially as tantalite) is a dull black metallic ore from which the elements niobium and tantalum are extracted. The niobium-dominant mineral in coltan is columbite (after niobium's original American name, columbium), and the tantalum-dominant mineral is tantalite. Venezuela, Guyana have highest reserves in South American continent. Same for African countries. Current with many uses in the telecom devices and others.
