opal blue squareImitatiopn opal, cabochon oval Subgroups opal nameØtypeType of cutPUitem No.opal6,0x6,0 mmsyntheticCabochon square1488306opal8,0x8,0 mmsyntheticCabochon square1488308opal10,0x10,0 mmsyntheticCabochon square1488310