Euxenite
| Euxenite | |
|---|---|
Euxenite from Norway, around 11 cm of size | |
| General | |
| Category | Oxide minerals |
| Formula | (Y,Ca,Ce,U,Th)(Nb,Ta,Ti) 2O 6 |
| IMA symbol | Eux |
| Strunz classification | 4.DG.05 |
| Crystal system | Orthorhombic |
| Space group | Pcmn (no. 62) |
| Identification | |
| Color | Black, brownish black, greenish black |
| Crystal habit | Massive, anhedral crystals in matrix |
| Twinning | Common on [201] |
| Cleavage | None |
| Fracture | Conchoidal to subconchoidal |
| Mohs scale hardness | 5.5 to 6.5 |
| Luster | Brilliant submetallic, waxy to resinous on fractures |
| Streak | Yellowish, grayish, or reddish brown |
| Diaphaneity | Opaque, translucent on thin edges |
| Specific gravity | 4.7 to 5 |
| Optical properties | Isotropic |
| Refractive index | n = 2.06 – 2.24 |
| Other characteristics | Metamict – originally crystalline, now amorphous due to radiation damage. Radioactive |
| References | |
Euxenite, or euxenite-(Y) (the official mineralogical name), is a brownish black mineral with a metallic luster.