gold diamond and sapphire ring

A large 18 carat yellow gold ring with an oval Ceylon sapphire (18.96 carat), on each side a brilliant cut diamond (app. 0.80 and 0.85 carat, Germany, circa 1980.

ring size: 21 mm. 11 ½ US.
weight: 24.15 gram.
width: 6 – 15 mm.
dimensions sapphire: 13.48 x 11.91 x 8.02 mm