Black opal, colored stone and diamond ring, circa 1930

The black opal of rectangular shape with cut-corner edges measuring approximately 16.5 by 15.0 mm., the shoulders set with tapering bands of calibré-cut emeralds alternating with calibré-cut sapphires within borders of small single-cut diamonds, mounted in platinum, size 5. Estimate 7,000—9,000 USD

Sotheby's. Important Jewels. 04 Feb 09. New York www.sothebys.com photo courtesy Sotheby's