Hematite
Round brilliant hematite
12.08 carats
© Rarestone.com
The name hematite (Greek - blood) is derived from the fact that, when cut, the saw coolant becomes coloured red. Hematite can be in reddish brown, ocherous masses, dark silvery-grey scaled masses, silvery-grey crystals, and dark-grey masses.
Formerly used as mourning jewelry, but today mainly for rings, bead necklaces and intaglio (deepened engravings). It takes a very high polish.
General Information |
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Other Names/Trade Names: | |
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Chemical Formula | Arthur Thomas, Gemstones (2009) |
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Hematite Simulants |
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Hematine is a trade name for an imitation of hematite with pressed and sintered iron oxide, from the USA. In contrast to hematite, it is slightly magnetic. - Gemstones of the world, Walter Schumann, 2001, p 162 |
Physical Properties of Hematite |
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Mohs Hardness | 6Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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Specific Gravity | 5.00 to 5.30Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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Tenacity | Brittle,ElasticAnthony et al, Handbook of mineralogy (2001) |
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Cleavage Quality | NoneWalter Schumann, Gemstones of the world (2001) More from other references |
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Fracture | Uneven,ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references |
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Optical Properties of Hematite |
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Refractive Index | 2.690 to 3.220Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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Optical Character | Uniaxial/-Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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Birefringence | 0.280Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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Pleochroism | Brownish red - yellowish red.Anthony et al, Handbook of mineralogy (2001) More from other references |
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Dispersion | Very strongAnthony et al, Handbook of mineralogy (2001) More from other references |
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Colour |
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Colour (General) | Black, steel gray, partly reddishUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) More from other references |
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Transparency | OpaqueHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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Lustre | MetallicHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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Fluorescence & other light emissions |
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Fluorescence (General) | NoneWalter Schumann, Gemstones of the world (2001) |
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Crystallography of Hematite |
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Crystal System | TrigonalHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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Habit | Crystals complex rhombohedral, pseudocubic, prismatic, rarely scalenohedral, to 13 cm, with triangular striations; thin tabular, to micaceous or platy, commonly in rosettes; radiating fibrous, reniform, botryoidal or stalactitic masses, columnar; earthy, granular, oolitic, concretionary.Anthony et al, Handbook of mineralogy (2001) More from other references |
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Geological Environment |
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Where found: | An accessory mineral in felsic igneous rocks, a late-stage sublimate in volcanic rocks, and in high-temperature hydrothermal veins. A product of contact metamorphism and in metamorphosed banded iron formations. A common cement in sedimentary rocks and a major constituent in oolitic iron formations. Abundant on weathered iron-bearing minerals.Anthony et al, Handbook of mineralogy (2001) |
Further Information |
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Mineral information: | Hematite information at mindat.org |
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Significant Gem Localities |
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| Myanmar | |
| Ted Themelis (2008) Gems & mines of Mogok | | Nigeria | |
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