An opal doublet and diamond cluster dress ring, the oval cabochon of 10.5 x 6.0 mm, displays strong play-of-colour ranging from green to purple on a dark blue ground, in a millgrain collet encompassed by an array of single-cut diamonds, between tapered shoulders, white metal marked '18 & PT', ring head approximately measures 1.5 x 1.0 cm, ring size P, total weight of item 2.7 grams.