Milarite
Switzerland
0.20 carats
Milarite is a rare beryllium silicate, that forms transparent to translucent colourless to pale yellow or green prismatic crystals, typically well formed.
A.Thomas (2009) reports: "The small pieces of facet rough that have been cut to date have all originated from a single African source".
| General Information | ||||||||||||||||||||||
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| Chemical Formula |
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| Physical Properties of Milarite | ||||||||||||||||||||||
| Mohs Hardness | 5.5 to 6, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Specific Gravity | 2.52 to 2.60, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Tenacity | Brittle, Gemstones (2009) | |||||||||||||||||||||
| Cleavage Quality | Imperfect, Gemstones (2009) | |||||||||||||||||||||
| Fracture | Uneven,Conchoidal, Gemstones (2009) | |||||||||||||||||||||
| Optical Properties of Milarite | ||||||||||||||||||||||
| Refractive Index | 1.529 to 1.560, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Optical Character | Uniaxial/-, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Birefringence | 0.000 to 0.011, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Colour | ||||||||||||||||||||||
| Colour (General) | Yellow, colourless, white, green., Gemstones of the world (2001) More from other references | |||||||||||||||||||||
| Transparency | Transparent, Gemmological Tables (2004) More from other references | |||||||||||||||||||||
| Lustre | Vitreous, Gemstones of the world (2001) More from other references | |||||||||||||||||||||
| Fluorescence & other light emissions | ||||||||||||||||||||||
| Fluorescence (General) | Common weak to moderate chalky green (and phosphorescence), Blue Chart Gem Identification (2010) | |||||||||||||||||||||
| Crystallography of Milarite | ||||||||||||||||||||||
| Crystal System | Hexagonal, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Habit | Prismatic crystals, typically well formed, Gems, Sixth Edition (2006) More from other references | |||||||||||||||||||||
| Geological Environment | ||||||||||||||||||||||
| Where found: | Milarite is found in vugs in granites and syenites or in hydrothermal veins., Gems, Sixth Edition (2006) | |||||||||||||||||||||
| Inclusions in Milarite | ||||||||||||||||||||||
| May show thin elongated thread-like inclusions - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 7 | ||||||||||||||||||||||
| Further Information | ||||||||||||||||||||||
| Mineral information: | Milarite information at mindat.org | |||||||||||||||||||||
| Significant Gem Localities | ||||||||||||||||||||||
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