Note the dark backing on this thin piece of opal. Photo courtesy of liveauctioneers.com and Jasper52.
Assembled Opaque Blue Play-of-Color Black Opal Cabochon
Note the dark backing on this thin piece of opal. Photo courtesy of liveauctioneers.com and Jasper52.
Article: Common Gemstone Treatments Cheat Sheet
Credit: Jasper52
| Gemstone | Opal Stone, Black Opal, Precious Opal |
| Natural or man made | Assembled |
| Gem State | Cabochon |
| Color | Blue |
| Transparency | Opaque |
| Photo phenomena | Play of Color |