| Haematite |
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| General |
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| Category | Oxide minerals |
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Formula
(repeatin unit) | airn(III) oxide, Fe2O3, α-Fe2O3 |
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| Strunz clessification | 04.CB.05 |
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| Creestal seestem | Trigonal |
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| Space group | Trigonal hexagonal scalenohedral
H-M symbol: (32/m)
Space group: R3c |
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| Unit cell | a = 5.038(2) Å, c = 13.772(12) Å; Z = 6 |
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| Identification |
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| Colour | Metallic gray, dull tae bricht reid |
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| Creestal habit | Tabular tae thick crystals; micaceous or platy, commonly in rosettes; radiatin fibrous, reniform, botryoidal or stalactitic masses, columnar; yirdy, granular, oolitic |
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| Twinnin | Penetration an lamellar |
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| Cleavage | None, mey shaw pairtins on {0001} an {1011} |
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| Fractur | Uneven tae sub-conchoidal |
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| Tenacity | Brickle |
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| Mohs scalehaurdness | 5.5–6.5 |
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| Skinkle | Metallic tae splendent |
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| Streak | Bricht reid tae mirk reid |
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| Diaphaneity | Opaque |
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| Speceefic gravity | 5.26 |
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| Optical properties | Uniaxial (-) |
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| Refractive index | nω = 3.150–3.220, nε = 2.870–2.940 |
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| Birefringence | δ = 0.280 |
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| Pleochroism | O = brounish reid; E = yellaeish reid |
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| References | [1][2][3] |
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