Pyrophanite
Pyrophanite is a manganese titanium oxide mineral with formula: MnTiO3. It is a member of the ilmenite group. It is a deep red to greenish black mineral which crystallizes in the trigonal system.
| Pyrophanite | |
|---|---|
| General | |
| Category | Oxide mineral |
| Formula (repeating unit) | MnTiO3 |
| IMA symbol | Pph |
| Strunz classification | 4.CB.05 |
| Dana classification | 4.3.5.3 |
| Crystal system | Trigonal |
| Crystal class | Rhombohedral (3) (same H-M symbol) |
| Space group | R3 |
| Unit cell | a = 5.13948(7) Å, c = 14.2829(4) Å; Z = 6 |
| Identification | |
| Color | Deep blood-red to greenish black |
| Crystal habit | Rarely as rosettes of hexagonal plates, typically granular, scaly; occurs as exsolution lamenae in franklinite and spinel |
| Cleavage | Perfect on {0221} |
| Fracture | Conchoidal |
| Tenacity | Brittle |
| Mohs scale hardness | 5–6 |
| Luster | Submetallic |
| Streak | Ochre yellow |
| Diaphaneity | Subtranslucent to opaque |
| Specific gravity | 4.537 measured |
| Optical properties | Uniaxial (-) |
| Refractive index | nω = 2.481 nε = 2.210 |
| Birefringence | δ = 0.271 |
| Common impurities | Fe, Zn |
| References | |
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