Prase Opal
Tanzania
28.87 carats
© Palagems
Prase Opal 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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Prase Opal Gemstones by Size
This table shows distribution of Prase Opal 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:4.92 cts
Heaviest:28.87 cts
Average:16.90 cts
Total photos:2
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| General Information | ||||||||||
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| A variety or type of: | Common Opal, which is a variety of Opal | |||||||||
| Chemical Formula |
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| Physical Properties of Prase Opal | ||||||||||
| Mohs Hardness | 5 to 6.5, Blue Chart Gem Identification (2010) | |||||||||
| Specific Gravity | 1.98 to 2.25, Blue Chart Gem Identification (2010) | |||||||||
| Tenacity | Brittle, Gemstones of the world (2001) | |||||||||
| Cleavage Quality | None, Gemstones of the world (2001) | |||||||||
| Fracture | Conchoidal, Gemstones (2009) | |||||||||
| Optical Properties of Prase Opal | ||||||||||
| Refractive Index | 1.370 to 1.470, Blue Chart Gem Identification (2010) | |||||||||
| Optical Character | Isotropic, Gemstones (2009) | |||||||||
| Colour | ||||||||||
| Colour (General) | Apple-green, Gemstones of the world (2001) More from other references | |||||||||
| Causes of Colour | Green colour due to nickel-bearing inclusions, Opal (2007) | |||||||||
| Transparency | Transparent,Translucent,Opaque, Gemmological Tables (2004) | |||||||||
| Lustre | Vitreous, Gemstones (2009) | |||||||||
| Crystallography of Prase Opal | ||||||||||
| Crystal System | Amorphous, Blue Chart Gem Identification (2010) | |||||||||
| Habit | Massive, Gemstones (2009) | |||||||||
| Further Information | ||||||||||
| Mineral information: | Prase Opal information at mindat.org | |||||||||