Tantalite, [(Fe,Mn)(Ta,Nb)2O6], is a mineral group that is close to columbite. The two are often grouped together as a semi-singular mineral called 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 ferrotantalite and manganese-rich is tantalite-(Mn) or manganotantalite.
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 tantalites can be brown and translucent.
Tantalite has been found in Namibia, Nigeria, Canada, Madagascar, northern Europe, and Maine, California, Colorado and Virginia in the United States. Brazil has the world's largest reserve of tantalite (52.1%). As at 2006, 75% of world tantalite production comes from Australia.
Tantalite is also mined in Guainía and Vichada, Colombia. One of the first mining companies in Colombia to discover tantalite was Seminole Group Colombia, a company owned and operated by Seminole Enterprises Group of the United States.
Tantalite is used as an ore of tantalum and niobium and as mineral specimens and occurs in pegmatites. Some specimens may show a bluish iridescent tarnish and have demonstrated weak magnetism.
Tantalite is largely found mixed with columbite in an ore called coltan.
1. ^ mindat.org Tantalite
* Webmineral Tantalite-(Fe)