Black Opal
Lightning Ridge, Finch Co., New South Wales, Australia
1.34 carats
© Mineral Classics
Black Opal Gemstones by Size
This table shows distribution of Black 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:1.34 cts
Heaviest:16.01 cts
Average:6.23 cts
Total photos:3
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| General Information | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| A variety or type of: | Precious Opal, which is a variety of Opal | |||||||||||||||
| Chemical Formula |
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| Synthetic Black Opal | ||||||||||||||||
| Light-coloured opals can be darkened using several methods to simulate Black opals. - Opal, Lithographie, 2007 | ||||||||||||||||
| Physical Properties of Black Opal | ||||||||||||||||
| Mohs Hardness | 6 to 6.5, Blue Chart Gem Identification (2010) | |||||||||||||||
| Specific Gravity | 1.97 to 2.22, Gemmological Tables (2004) | |||||||||||||||
| Tenacity | Brittle, Gemstones of the world (2001) | |||||||||||||||
| Cleavage Quality | None, Gemstones of the world (2001) | |||||||||||||||
| Fracture | Conchoidal, Gemstones (2009) | |||||||||||||||
| Optical Properties of Black Opal | ||||||||||||||||
| Refractive Index | 1.370 to 1.470, Blue Chart Gem Identification (2010) | |||||||||||||||
| Optical Character | Isotropic, Gemstones (2009) | |||||||||||||||
| Birefringence | None, Gemstones of the world (2001) | |||||||||||||||
| Pleochroism | Absent, Gemstones of the world (2001) | |||||||||||||||
| Dispersion | None, Gemstones of the world (2001) | |||||||||||||||
| Colour | ||||||||||||||||
| Colour (General) | Dark background colour, Management Team (2012) | |||||||||||||||
| Transparency | Transparent,Translucent,Opaque, Gemmological Tables (2004) | |||||||||||||||
| Lustre | Vitreous, Gemstones (2009) | |||||||||||||||
| Crystallography of Black Opal | ||||||||||||||||
| Crystal System | Amorphous, Blue Chart Gem Identification (2010) | |||||||||||||||
| Habit | Massive, Gemstones (2009) | |||||||||||||||
| Further Information | ||||||||||||||||
| Mineral information: | Black Opal information at mindat.org | |||||||||||||||
| Significant Gem Localities | ||||||||||||||||
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