Natural Opal and Diamond 18 Carat Gold Cluster Ring For Sale at 1stDibs Long Oval Opal Diamond Cluster Ring 7850 Fine Opal Jewelry Victorian 18ct Gold Opal and Rose Cut Diamond Cluster Ring, Circa 1900 FINE BLACK OPAL AND DIAMOND CLUSTER RING sold at auction on 6th August Black Opal and Diamond Floral Cluster Ring Set in 18k Gold and Platinum Quality Natural Opal and Vs Diamond Platinum Cluster Ring For Sale at. A lovely white gold cluster ring. Features to the centre an oval white opal, 9x7mm, with an excellent play of colour. Retained by claws, and has an outer border of ten brilliant cut white diamonds, each 3mm diameter (estimated total one carat), colour H j, clarity Si. Head measures 14x12mm, depth 6mm, weight 4. 4grams. Purchased overseas, tests as 18 carat white gold, in almost near new condition with no wear at all. Size P, we can resize free of charge.