Opal gems synthesized through a process created by Pierre Gilson appear very natural. Gilson opals: cabochons from 3 to 6 cts. Photo © Joel E. Arem, PhD, FGA. Used with permission.
Lab-Created Opaque Red Opal Stone Cabochon
Opal gems synthesized through a process created by Pierre Gilson appear very natural. Gilson opals: cabochons from 3 to 6 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 |
| Natural or man made | Lab-made |
| Gem State | Cabochon |
| Color | Red, White, Brown |
| Transparency | Opaque |