Wiktionary
tantite
n. (context mineralogy English) A triclinic-pedial colorless mineral containing oxygen and tantalum.
Wikipedia
Tantite
Tantite is a rare tantalum oxide mineral with formula: Ta O. 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, Russia. It has also been reported from a pegmatite complex in Florence County, Wisconsin. Associated mineral species include elbaite, lepidolite, spodumene, columbite-tantalite, wodginite, and microlite.