Jewellery, Watches and Objects of Vertu to include the personal archive of Louis Osman, goldsmith and architect

A rubellite tourmaline and diamond set ring, the oval mixed-cut rubellite claw set above a mount and shoulders set with small brilliant-cut diamonds, mounted in white precious metal, stamped ‘750’, together with narrow band ring set with a line of five small brilliant-cut diamonds, white precious metal mount stamped ‘585’, first ring size K½. £300-400