Tantite is a rare tantalum mineral with formula: Ta 5. Tantite forms transparent microscopic colorless triclinic - pedial crystals with an adamantine luster. It has a Mohs hardness of 7 and a high specific gravity of 8.45. Chemical analyses show minor inclusion (1.3%) of niobium oxide.
It was first described in 1983 for an occurrence in a pegmatite in the Kola peninsula. It has also been reported from a pegmatite complex in Florence County, Wisconsin. Associated mineral species include elbaite, columbite-tantalite , and microlite.