Black Onyx, also known as black agate, is dyed black chalcedony. Chalcedony is composed of microscopic quartz crystals not visible to the naked eye. Natural black chalcedony is exceptionally rare — virtually all black chalcedony on the market is grey chalcedony that has been chemically treated to achieve its characteristic deep, uniform black color. Black Onyx has long been one of the top-selling chalcedony gemstones and was a hallmark material in Art Deco jewelry design. These genuine cabochons feature a cushion buff-top double-bevel cut with a pre-drilled hole, making them well suited for a wide range of jewelry fabrication applications.
Features
- Genuine black onyx — dyed black chalcedony
- Cushion buff-top double-bevel cut profile
- Pre-drilled hole for easy setting or stringing
- Uniform opaque black color throughout
- Rich history in Art Deco and fine jewelry traditions
- Care: Clean with warm, soapy water; ultrasonic and steam cleaning are generally safe
Specifications
| Stone Type |
Black Onyx (dyed black chalcedony) |
| Treatment |
Dyed |
| Color |
Uniform opaque black |
| Cut |
Cushion buff-top double bevel |
| Feature |
With hole |
| Cleaning |
Warm soapy water; ultrasonic and steam cleaning are generally safe |
Available Options
| Part # |
Stone Size |
| 947-463 |
14mm x 12mm |
| 947-464 |
16mm x 12mm |
California Prop 65 Warning: