JONC RING In yellow gold, set with a brilliant-cut diamond weighing approximately 2 ct, surrounded by black enamel. Hallmarked by the master. TDD: 49; US: 5 (subject to change). An 18k gold and black enamel ring set with a brilliant cut diamond weighing approximately 2 ct. RC : Minor damage to the enamel. Marked by Juif & Fils in Paris. Estimated colour: G, estimated clarity: VS. Gross weight: 10.9 g (18k - 750).