Onyx
Russia
3.81 carats
© Brian Kosnar - Mineral Classics
The name Onyx has its origin in the Greek language and means "fingernail", probably because of its weak transparency.
Onyx 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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Onyx Gemstones by Size
This table shows distribution of Onyx 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:3.55 cts
Heaviest:3.81 cts
Average:3.66 cts
Total photos:4
Do you have a larger Onyx? Why not upload a photo?
| General Information | |
|---|---|
| A variety or type of: | Agate, which is a variety of Chalcedony, which is a variety of Quartz |
| Onyx Treatments | |
| Black chalcedony ("onyx") is assumed to be dyed - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 7 | |
| Physical Properties of Onyx | |
| Mohs Hardness | 6.5 to 7, Blue Chart Gem Identification (2010) More from other references |
| Specific Gravity | 2.55 to 2.70, Blue Chart Gem Identification (2010) |
| Optical Properties of Onyx | |
| Refractive Index | 1.530 to 1.543, Blue Chart Gem Identification (2010) |
| Optical Character | Uniaxial/+, Gemmological Tables (2004) |
| Colour | |
| Colour (General) | Straight color bands (black with white layer), Blue Chart Gem Identification (2010) More from other references |
| Transparency | Opaque, Blue Chart Gem Identification (2010) More from other references |
| Crystallography of Onyx | |
| Crystal System | Trigonal, Gemmological Tables (2004) |
| Further Information | |
| Mineral information: | Onyx information at mindat.org |