A black sapphire and diamond ring, the cushion-shaped sapphire flanked with three circular-cut

A black sapphire and diamond ring, the cushion-shaped sapphire flanked with three circular-cut diamonds to each side in textured 18ct white gold shank, London hallmarks for 1977, size K

Accompanied by report number 22194 dated 1st October 2022 from The Gem & Pearl Laboratory stating that the dark blue to black, rectangular cushion-shaped sapphire measures 20.0 x 18.8 x 10.2mm and has no evidence of heat treatment. The geological occurrence is common to Thailand, Australia, East Africa, etc