Opal 9.90ct,Natural and Untreated,Oval Shape,Excellent Cut,Dimensions of Opal = 15.40 * 12.20 * 8.50mm,Oval Cabochon,Opal is sourced from Ethiopia,October Birthstone,Ring Size = 5.50,Ring Weight = 5.60g,Ring has a Platinum Finish and is 925 Solid Sterling Silver.