Pyrophanite
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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.
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Pyrophanite | |
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General | |
Category | Oxide mineral |
Formula (repeating unit) | MnTiO3 |
IMA symbol | Pph[1] |
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 | [2][3][4] |
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