Tongbaite
Type of rare mineral
From Wikipedia, the free encyclopedia
Tongbaite is a rare mineral that has the chemical formula Cr3C2, or chromium carbide.
| Tongbaite | |
|---|---|
| |
| General | |
| Category | Carbide mineral |
| Formula | Cr3C2 |
| IMA symbol | Tgb[1] |
| Strunz classification | 1.BA.15 |
| Crystal system | Orthorhombic |
| Crystal class | Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) |
| Space group | Pnma |
| Unit cell | a = 5.52 Å, b = 11.48 Å c = 2.82 Å; Z = 4 |
| Identification | |
| Color | Pale brownish yellow; pale violet in reflected light |
| Crystal habit | Prismatic crystals, pseudohexagonal |
| Tenacity | Brittle |
| Mohs scale hardness | 8.5 |
| Luster | Metallic |
| Diaphaneity | Opaque |
| Specific gravity | 6.64 calculated |
| References | [2][3][4] |
It was first described in 1983 for an occurrence in Liu village, Tongbai County (桐柏县), Henan Province, China and named for the locality.[3] It occurs in an ultramafic rock deposit.[2] It has also been found in the Tibet Autonomous Region and the Isovsky District, in the Urals of Russia.[3]
