Diamond ring, Tiffany & Co. The round brilliant-cut diamond weighing 1.33 carats is claw-set and mounted in 18ct gold and iridium platinum, size K1/2, signed Tiffany & Co. Accompanied by a GSL report numbered AA51726/1, dated 14 June 2013, stating that the 1.33 carat diamond is H colour, and VS2 clarity.