Pearl Square Ring 12 mm with 18ky/Sterling guard rings

Sterling silver, square ring with 12 mm white mabe pearl rimmed with 18k yellow gold.  Tapered band 9 mm to 7 mm  wide x 1.5 mm thick.   Flanked by 18k yellow gold and sterling square rings inset with 5 x .02 ct diamonds. 3 mm wide x 1.5 mm thick