| Tantite | |
|---|---|
| General | |
| Category | Oxide minerals | 
| Formula | Ta 2 O 5 | 
| IMA symbol | Tan [1] | 
| Strunz classification | 4.EA.05 | 
| Dana classification | 04.06.06.01 | 
| Crystal system | Triclinic | 
| Crystal class | Pedial (1) (same H-M symbol) | 
| Space group | P1 | 
| Unit cell | a = 3.8  Å, b = 3.79 Å c = 35.74 Å; β = 90.18°; Z = 6 | 
| Identification | |
| Formula mass | 441.89 g/mol | 
| Color | Colorless | 
| Cleavage | None | 
| Mohs scale hardness | 7 | 
| Luster | Adamantine | 
| Streak | White | 
| Diaphaneity | Transparent | 
| Specific gravity | 8.55 | 
| Density | 8.45 g/cm3 | 
| Optical properties | Biaxial | 
| References | [2] [3] | 
Tantite is a rare tantalum oxide mineral with formula: Ta 2 O 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, 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.