Ice Dragon Handmade large Kyoto Solid Opal ring in Stone and Sterling Silver 925 Setting . Stone dimensions: 15 x 12 mm, cabochon height: 7 mm. Total weight: approximately 7.3 g (36.5 carats). The ring is adjustable from approximately 16 mm (UK size J ½ or US size 5) to 20 mm (UK size U ½ or US size 10½).