Platinum Black Opal and Diamond ring. Circa: 1900 - 1930 The black opal has brilliant harlequin pattern of blue and green color. The oval shape cabochon cut opal measures approx. 12.00 x 11.00 m.m., and weighs approx. 4.25 carats. 14 (Fourteen) Old European Cut Diamonds bezel- set weighing approx. 0.71 carat total. Diamonds are colorless, and VS - SI in clarity. The diameter of the top of the ring measures 3/4" x 5/8 ". The ring size is 4 1/2. Stamped in shank " IRID PLAT The ring weighs 6.20 grams. The ring was gently loved, which means that there is slight wear. Wear commensurate with age and use. Still a classic. Free Shipping