Tantalite Wikipedia
The mineral group tantalite [(Fe, Mn)Ta 2 O 6] is the primary source of the chemical element is chemically similar to columbite, and the two are often grouped together as a semisingular mineral called coltan or "columbitetantalite" in many mineral guides. However, tantalite has a much greater specific gravity than columbite (+ compared to columbite''s ).