| opal → AtLocation → australia | 0.69 | |
| opal → AtLocation → mexico | 0.64 | |
| opal → AtLocation → cretaceous rock | 0.55 | |
| opal → AtLocation → south australia | 0.53 | |
| opal → AtLocation → coober pedy | 0.50 | |
| opal → AtLocation → ethiopia | 0.48 | |
| opal → AtLocation → lightning ridge | 0.41 | |
| opal → AtLocation → indonesia | 0.41 | |
| opal → AtLocation → white | 0.35 | |
| opal → AtLocation → japan | 0.25 |