Montebrasite
Brazil
2.56 carats
© Rarestone.com
Montebrasite forms attractive, colourless, bright yellow-green, sometimes blue, pink and pale brown, equant to short-prismatic crystals, twinning is common.
Montebrasite Gemstones by Colour
This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
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Montebrasite Gemstones by Size
This table shows distribution of Montebrasite gemstone sizes that are listed on this site. This can give a good indication as to the general availability of this gemstone in different sizes.
Contributed photos
Lightest:2.56 cts
Heaviest:21.55 cts
Average:7.67 cts
Total photos:6
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| General Information | ||||||||||||||||||||||
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| Chemical Formula |
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| Physical Properties of Montebrasite | ||||||||||||||||||||||
| Mohs Hardness | 5.5 to 6, Gemstones of the world (2001) More from other references | |||||||||||||||||||||
| Specific Gravity | 2.98 to 3.10, Blue Chart Gem Identification (2010) | |||||||||||||||||||||
| Tenacity | Brittle, Handbook of Mineralogy (2001) | |||||||||||||||||||||
| Cleavage Quality | Perfect, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Fracture | Uneven,Sub-Conchoidal, Handbook of Mineralogy (2001) | |||||||||||||||||||||
| Optical Properties of Montebrasite | ||||||||||||||||||||||
| Refractive Index | 1.578 to 1.646, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Optical Character | Biaxial/+, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Birefringence | 0.020 to 0.030, Blue Chart Gem Identification (2010) | |||||||||||||||||||||
| Colour | ||||||||||||||||||||||
| Colour (General) | Colourless, yellowish, light green, light blue, white, pink., Gemstones of the world (2001) More from other references | |||||||||||||||||||||
| Transparency | Transparent, Gemstones of the world (2001) More from other references | |||||||||||||||||||||
| Lustre | Vitreous, Gemstones of the world (2001) More from other references | |||||||||||||||||||||
| Fluorescence & other light emissions | ||||||||||||||||||||||
| Fluorescence (Long-Wave UV) | Inert to weak green, Blue Chart Gem Identification (2010) | |||||||||||||||||||||
| Phosphorescence | May phosphoresce light blue to LW and SW, Blue Chart Gem Identification (2010) | |||||||||||||||||||||
| Crystallography of Montebrasite | ||||||||||||||||||||||
| Crystal System | Triclinic, Blue Chart Gem Identification (2010) | |||||||||||||||||||||
| Habit | Crystals typically equant, may be short to long prismatic, to 10 cm; as coarse cleavable or blocky to rounded nodular masses., Handbook of Mineralogy (2001) | |||||||||||||||||||||
| Geological Environment | ||||||||||||||||||||||
| Where found: | A late primary and secondary mineral in zoned granite pegmatites; may be an ore of lithium., Handbook of Mineralogy (2001) | |||||||||||||||||||||
| Further Information | ||||||||||||||||||||||
| Mineral information: | Montebrasite information at mindat.org | |||||||||||||||||||||
| Significant Gem Localities | ||||||||||||||||||||||
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