Colleen Lopez 8.70ct Rainbow Quartz Mystic Topaz and Tanzanite Sterling Silver Ring Size 7 Design Information; Sterling silver ring has prong-set, oval rainbow quartz at center; Quartz bordered by prong-set, round tanzanite; Openwork shank; Measurements: Approx. 13/16"L x 5/8"W; x 5/16'H; shank 1/8"W; Metal Type: Sterling silver; Metal Color: White; Metal Stamp: .925; Plating: Rhodium; Finish: Polished; Total Carat Weight: 8.70ct; Enhanced Purple "Rainbow" Quartz Oval (8x12mm); 7.98ct Imported.