Onyx
If onyx is a variety of agate, then this specimen certainly qualifies. The striking black-and-white bullseye-like layer of chalcedony actually grew on a matrix of terminated crystalline quartz. 7.0 x 5.8 x 5.5 cm, Minas Gerais, Southeast Region, Brazil. © Rob Lavinsky, www.iRocks.com. Used with permission.
Article: Onyx Value, Price, and Jewelry Information
Credit: www.iRocks.com
| Gemstone | Quartz, Chalcedony, Onyx |
| Natural or man made | Natural |
| Origin | Brazil |
| Origin details | Minas Gerais, Southeast Region |
| Height | 70 |
| Width | 58 |
| Depth | 55 |
| Gem State | Other |
| Color | White, Black |
| Transparency | Translucent |
| Multi-color | Bi-color |