Opal Oval Shape Cabochon. Great Size - Fine Color Quality. Weight: 6.63 ct Size: 16.73 x 11.04 x 6.92 mm. Color: White base with a vivid play of colors. Luster: Multicolor. Treatment: No indications of treatment. ALGT Certificate Report no. 83429353. Top gem—Great size, perfect for a centerpiece—Top luster—The lab mentioned it as a 'Fine Color Quality' gem. Unique to Opal, ‘play of color’ is the attractive flashes of colorful brilliance that change with the angle of observation. An Opal with a play of color with three or more hues is called a multicolor. October’s birthstone, Opal, comes from the Greek ‘opallios’, meaning ‘to see a change Shipment with a reliable service provider will be trackable and insured. Duties and taxes will be the Buyer's responsibility. IMPORTANT: The pictures were taken under white and yellow light with magnification on dark backgrounds, intended to be displayed as accurately as possible. We have tried to capture as real colors/luster as possible, but they may differ slightly.