Calcite

Cobalt-bearing Calcite
Spain
6.44 carats
© Rarestone.com
Calcite is named after Latin "calx" - lime. It is a very common mineral with wide range of colours and forms.
Attractive specimens are faceted or used for cabochons and carved ornamental objects.
Calcite may exhibit fluorescence, phosphorescence, thermoluminescence and/or triboluminescence.
| General Information |
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| Varieties/Types: | |
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| Chemical Formula | Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) More from other references |
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| Calcite Treatments |
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| Massive variety often dyed green to imitate jadeite. Chelsea: commonly red. Solvent test. May be impregnated with wax or plastic: hot point test - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 9 |
| Physical Properties of Calcite |
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| Mohs Hardness | 3Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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| Specific Gravity | 2.67 to 2.73Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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| Cleavage Quality | PerfectHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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| Fracture | ConchoidalArthur Thomas, Gemstones (2009) |
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| Optical Properties of Calcite |
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| Refractive Index | 1.486 to 1.658Herve 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 | 0.172Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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| Pleochroism | NilArthur Thomas, Gemstones (2009) |
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| Dispersion | e ray-0.008 to o ray-0.017Arthur Thomas, Gemstones (2009) |
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| Colour |
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| Colour (General) | White, yellowish, pink, bluish, orange, colourlessUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) More from other references |
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| Causes of Colour | Pink, CO2+W. William Hanneman, Pragmatic Spectroscopy For Gemologists (2011) |
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| Transparency | Transparent,Translucent,OpaqueUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) More from other references |
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| Lustre | Vitreous,ResinousArthur Thomas, Gemstones (2009) |
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| Fluorescence & other light emissions |
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| Fluorescence (Long-Wave UV) | Inert to strong reaction, commonly pinkish-redHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) |
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| Crystallography of Calcite |
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| Crystal System | TrigonalHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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| Habit | Scalenohedrons, rhombohedrons, stalactiteArthur Thomas, Gemstones (2009) |
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| Geological Environment |
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| Where found: | A major rock-forming mineral. It occurs in limestones, marbles, chalks, a common cement in clastic sedimentary rocks, and as gangue in hydrothermal veins; in alkalic to mafic igneous rocks; common as speleothems in caves.Anthony et al, Handbook of Mineralogy (2001) |
| Further Information |
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| Mineral information: | Calcite information at mindat.org |
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| Significant Gem Localities |
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| Colombia | | |
| | | DR Congo | | |
| [var: Cobalt-bearing Calcite] |
- Sicomines copper-cobalt project
| [var: Cobalt-bearing Calcite] | | Iceland | | |
| mindat.org | | Myanmar | | |
| Ted Themelis (2008) Gems & mines of Mogok | |
| Ted Themelis (2008) Gems & mines of Mogok |
- Pein-Pyit (Painpyit; Pyan Pyit)
| Ted Themelis (2008) Gems & mines of Mogok | | Peru | | |
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