Platinum and diamond ring, René Boivin, circa 1935

The platinum band of bombé form inset with an oval diamond weighing approximately 3.50 carats, size 6, French assay mark. Estimate 15,000—20,000 USD

NOTE: Accompanied by a certificate of authenticity from Boivin, dated October 2006, issued by Françoise Cailles.

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