Boucheronemerald and diamond ring. Set with a round old cutnatural emerald to centre in a rubover setting with a weight of 0.15 carats, flanked by two curving rows of round brilliant cutdiamonds in open backgrain settings, fourteen in total with an approximate combined weight of 0.40 carats, to a circular cluster with an articulated scalloped and fluted yellow gold upper piece rotating to expose and cover the diamonds as preferred, flanked by heavy trumpeted shoulders to a solid D-shapeshank. Marked 18 carat yellow gold, signed 'BOUCHERON', numbered 'B645 11471', 'OR 750', maker's mark for Boucheron, French, circa 1970s.