Gilson synthetic opals. Photo © Joel E. Arem, PhD, FGA. Used with permission.
Lab-Created Opaque Red Play-of-Color Opal Stone Cabochon
Gilson synthetic opals. Photo © Joel E. Arem, PhD, FGA. Used with permission.
Article: Appraising Opals
Credit: Joel E. Arem, PhD, FGA
| Gemstone | Opal Stone |
| Natural or man made | Lab-made |
| Origin details | Gilson synthetic |
| Gem State | Cabochon |
| Color | Red, White, Black |
| Transparency | Opaque |
| Photo phenomena | Play of Color |