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

A sapphire and diamond set dress ring, the slightly domed abstract cluster of brilliant-cut diamonds and oval mixed-cut sapphires, one replaced with blue stone, all claw set, accented with textured ribbon detail, mounted in white precious metal, shank stamped ‘18ct’, total diamond weight approximately 1.1 carats, ring size O. £800-1000