Semi-black opal: Australia (approximately 10 cts). Photo © Joel E. Arem, PhD, FGA. Used with permission.
Opaque Black Play-of-Color Black Opal Cabochon from Australia
Semi-black opal: Australia (approximately 10 cts). Photo © Joel E. Arem, PhD, FGA. Used with permission.
Article: Opal Stones and Gems: Value, Price, and Jewelry Information
Credit: Joel E. Arem, PhD, FGA
| Gemstone | Opal Stone, Black Opal, Precious Opal |
| Natural or man made | Natural |
| Origin | Australia |
| Gem State | Cabochon |
| Color | Black |
| Transparency | Opaque |
| Photo phenomena | Play of Color |