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, lustrous black color. Black Onyx has long been one of the top-selling chalcedony stones in the jewelry market and was widely featured in Art Deco designs. These cushion buff top single bevel cabochons offer a uniform opaque black appearance, making them a versatile choice for rings, pendants, bracelets, and other fine jewelry settings.
To care for Black Onyx, clean with warm soapy water. Use of an ultrasonic or steam cleaner is generally considered safe for these stones.
Features
- Genuine Black Onyx (dyed black chalcedony)
- Cushion buff top with single bevel profile
- Uniform opaque black color throughout
- Chemically dyed for consistent, deep black appearance
- Suitable for use in rings, pendants, earrings, and other jewelry settings
- Safe for ultrasonic and steam cleaning
Specifications
| Stone Type |
Black Onyx (Dyed Black Chalcedony) |
| Cut Style |
Cushion Buff Top, Single Bevel |
| Treatment |
Dyed |
| Opacity |
Opaque |
| Color |
Uniform Opaque Black |
| Care |
Warm soapy water; ultrasonic and steam cleaning generally safe |
| Tags |
Cabochons, Genuine Cabochons, Resale |
Available Options
| Part # |
Size |
| 947-410 |
12x10mm |
| 947-411 |
9x7mm |
| 947-412 |
14x10mm |
| 947-413 |
14x12mm |
| 947-414 |
16x12mm |