Famously clear Gem Opal, bright color bars appearing out of a clear polished oval stone. .6 cts. Kelley Fields, Lightning Ridge, Australia. Locality:…….Kelley Fields, Lightning Ridge, Australia Length……….9mm Width:…….….6mm Thick:…………..2.5mm Weight:………. (point) .6 cts Back:…………..Polished, Cut Flat Stock…………….070-KELOP-15