Pseudobrookite
Pseudobrookite is an iron titanium oxide mineral with formula: Fe2TiO5 or (Fe3+,Fe2+)2(Ti,Fe2+)O5.
| Pseudobrookite | |
|---|---|
Spray of pseudobrookite needles from Topaz Mountain in Utah (size: 2.7 x 2.0 x 1.6 cm) | |
| General | |
| Category | Oxide mineral |
| Formula (repeating unit) | Fe2TiO5 |
| IMA symbol | Pbrk |
| Strunz classification | 4.CB.15 |
| Crystal system | Orthorhombic |
| Crystal class | Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) |
| Space group | Bbmm |
| Unit cell | a = 9.81 Å, b = 9.95 Å, c = 3.73 Å; Z = 8 |
| Identification | |
| Color | Dark reddish brown, brownish black, black |
| Crystal habit | Prismatic to needle like, striated |
| Cleavage | Distinct on {010} |
| Fracture | Uneven to subconchoidal |
| Mohs scale hardness | 6 |
| Luster | Adamantine, greasy, metallic |
| Streak | Brown |
| Diaphaneity | Opaque, transparent in thin splinters |
| Specific gravity | 4.33–4.39 |
| Optical properties | Biaxial (+) |
| Refractive index | nα = 2.350 nβ = 2.390 nγ = 2.420 |
| Birefringence | δ = 0.070 |
| 2V angle | Measured: 50° |
| References | |
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.