Lady's 18K White & Yellow Gold Gregg Ruth Oval Cut Blue & Yellow Sapphire & Diamond Ring. Ring Size: 7 (Can be Resized to Fit Most Any Finger) Contains: 1 Oval Cut Blue Natural Sapphire. 2 Oval Cut Yellow Natural Sapphires. Weight Approx: 3.14cttw. 60 Round Brilliant Cut Natural Diamonds. Weight Approx: 1.64cttw. From the highly acclaimed workshops of Gregg Ruth. Amongst the elegant & fashionable, there are two big names today: Gregg Ruth and Roberto Coin. Both are rarely available at a discount and always exquisite.