15.00 CT BLUE TOPAZ IN 18K WHITE GOLD: 18K white gold topaz and diamond ring contains one rectangular mixed cut topaz. Weight: 15.00 Ct. ''Sky'' blue in color. Approx. 108 round full cut diamonds. Weight: .50 Ct. Approx. Rated VS-SI in clarity and G-H in color. The topaz and diamonds are prong set. Size 6.5. Mounting Weight: 6.0 grams.