A George III sapphire and diamond cluster ring, Sri Lanka, no heat

A George III sapphire and diamond cluster ring, c.1810, set with a cushion-shaped sapphire within open-backed gold cut-down collet setting, within a surround of old cushion-shaped diamonds in silver on gold, with foliate engraved shoulders in gold, fluted shank, size I 1/2

Accompanied by report number 80272-95 dated 19 August 2020 from GCS stating that the cushion-cut sapphire is a natural sapphire with no indications of heat treatment. Origin: Sri Lanka (Ceylon).