Dumortierite
Madagascar
0.15 carats
© irocks.com
Dumortierite 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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Dumortierite Gemstones by Size
This table shows distribution of Dumortierite 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:0.06 cts
Heaviest:8.18 cts
Average:3.16 cts
Total photos:14
Do you have a larger Dumortierite? Why not upload a photo?
| General Information | ||||||||||||||||||||||
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| Chemical Formula |
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| Physical Properties of Dumortierite | ||||||||||||||||||||||
| Mohs Hardness | 7 to 8.5, Gemstones of the world (2001) Aggregates, mainly cut, have hadrness of 7; crystals - 8.5More from other references | |||||||||||||||||||||
| Specific Gravity | 3.26 to 3.41, Gemstones of the world (2001) More from other references | |||||||||||||||||||||
| Cleavage Quality | Good, Gemstones of the world (2001) More from other references | |||||||||||||||||||||
| Fracture | Conchoidal, Gemstones of the world (2001) More from other references | |||||||||||||||||||||
| Optical Properties of Dumortierite | ||||||||||||||||||||||
| Refractive Index | 1.669 to 1.723, Blue Chart Gem Identification (2010) Rare red-brown crystals +/- 1.669More from other references | |||||||||||||||||||||
| Optical Character | Biaxial/-, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Birefringence | 0.011 to 0.037, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Pleochroism | Strong trichroism for rare red-brown crystals: black - red brown - brown, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Dispersion | None, Gemstones of the world (2001) More from other references | |||||||||||||||||||||
| Colour | ||||||||||||||||||||||
| Colour (General) | Dark blue, violet-blue, red-brown, colourless, Gemstones of the world (2001) More from other references | |||||||||||||||||||||
| Transparency | Translucent,Opaque, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Lustre | Vitreous, Gemstones (2009) Dull | |||||||||||||||||||||
| Fluorescence & other light emissions | ||||||||||||||||||||||
| Fluorescence (General) | Weak; blue - blue-white - violet, Gemstones of the world (2001) | |||||||||||||||||||||
| Fluorescence (Short Wave UV) | Inert to chalky blue, often intergrown with quartz, Blue Chart Gem Identification (2010) | |||||||||||||||||||||
| Crystallography of Dumortierite | ||||||||||||||||||||||
| Crystal System | Orthorhombic, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Habit | Commonly fibrous aggregate, Gemmological Tables (2004) More from other references | |||||||||||||||||||||
| Geological Environment | ||||||||||||||||||||||
| Where found: | Dumortierite occurs in pegmatite veins or in aluminium-rich regionally metamorphosed rocks., Gems, Sixth Edition (2006) | |||||||||||||||||||||
| Further Information | ||||||||||||||||||||||
| Mineral information: | Dumortierite information at mindat.org | |||||||||||||||||||||
| Significant Gem Localities | ||||||||||||||||||||||
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