Vintage Australian dark opal in etched gold setting in size 5-6.

This opal ring is from the 70's when a traveling opal shop came from Australia to Edmonton to sell jewelry at Klondike Days. Judging from the price of it then it seems to be real gold but is marked Ct only. Maybe the carat amount has rubbed off?! The etching on 1 side is really beautiful and the gorgeous opal sits up 1/4" from the ring. It measures 17mm across or just a sniff over 5/8". It has shades of pink, blue mauve and red. Just stunning!