Ebony and diamond ring, René Boivin, circa 1955

The tapering gold and ebony band of bombé form decorated with a panel of pavé-set round diamonds weighing approximately 2.60 carats, mounted in 18 karat gold, size 4½, signed René Boivin, maker's mark, assay mark. Estimate 5,000—7,000 USD

NOTE: Accompanied by a certificate of authenticity from Boivin, dated February 2007, issued by Françoise Cailles.

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