The mineral group tantalite [(Fe, Mn)Ta2O6] is the primary source of the chemical element tantalum.
It is chemically similar to Columbite, and the two are often grouped together as a semi-singular mineral called Coltan or “Columbite-tantalite” in many mineral guides.
However, tantalite has a much greater specific gravity than Columbite (8.0+ compared to columbite’s 5.2). Iron-rich tantalite is the mineral tantalite-(Fe) or Ferro tantalite and manganese-rich is tantalite-(Mn) or mangano tantalite.
Tantalite is also very close to tapiolite. Those minerals have same chemical composition, but different crystal symmetry orthorhombic for tantalite and tetragonal for tapiolite.
Tantalite is black to brown in both color and streak. Manganese-rich tantalite’s can be brown and translucent.
Columbite, also called niobite, niobite-tantalite and Columbite [(Fe, Mn)Nb2O6], is a black mineral group that is an ore of niobium. It has a submetallic cluster and a high density and is a niobate of iron and manganese.
Gold is a chemical element with symbol Au (from Latin: aurum) and atomic number 79. In its purest form, it is a bright, slightly reddish yellow, dense, soft, malleable and ductile metal. Chemically, gold is a transition metal and a group 11 element.
Niobium, formerly columbium, is a chemical element with symbol Nb (formerly Cb) and atomic number 41. It is a soft, grey, ductile transition metal, which is often found in the pyrochlore mineral, the main commercial source for niobium, and Columbite.