Jean Schlumberger for Tiffany & Co., gents opal ring, c. 1990, featuring a polished oval opal bezel set in 18ct rose gold with a brushed bombe 18ct yellow gold band, stamped 'Tiffany & Co. 750 Schlumberger Studios', with box, approx. Weight 18.9 grams size V1/2, Custom made for the original owner by Tiffany & Co. New York, c. 1990