gold ring with diamond and sapphire

An 18 carat yellow gold ring with an old brilliant cut diamond (0.5 ct, G-H-I), with a halo of eight trapezium cut sapphires, signed and numbered: Mellerio, 35357, France.

weight: 4.9 grams
size: 15.25 / 4.5 US
dimensions halo: 10 x 10 mm
width shank: 2 – 3 mm