A Ring 500/1000 platinum set with an oval cut sapphire with an approximate weight of 3.70 ct. and 28 brilliant cut diamonds with an approximate weight of 1.40 ct. Portuguese signs of use Lisbon mark (1938-1984), Carvalho & Castro Ldª makers' mark (1951) Dimensões (altura x comprimento x largura) - 12 (16,5 mm) cm; Peso - 6,7 g. Notes: Provenance: Jewelry collection of a soprano opera singer of the São Carlos National Opera House, Lisbon.