An Art Déco oval ring, 1920s-30s

gold, silver (unmarked), 3 old brilliant cut diamonds weighing in total approx. 0,40 ct G-H/SI, 18 diamonds in various cuts, 8 rose-cut diamonds weighing in total approx. 0,30 ct H-I/VS-SI, size: 8,5, weight: 3,39 g