While most Sterling opal shows black potch lines, some lapidaries cut cabochons without these features. Opal Auctions. Used with permission.
Lab-Created Opaque Green Play-of-Color Opal Stone Tumbled
While most Sterling opals show black potch lines, some lapidaries cut cabochons without these features. © Opal Auctions. Used with permission.
Article: Synthetic Opal Types
Credit: Opal Auctions
| Gemstone | Opal Stone |
| Natural or man made | Lab-made |
| Gem State | Tumbled |
| Color | Green |
| Transparency | Opaque |
| Photo phenomena | Play of Color |