An unheated Ceylon colour-change sapphire and diamond halo ring, centred with a cushion-cut sapphire of medium purplish-blue colour, measuring 13.1 x 10.3 x 8.35 mm, with an estimated weight of 10.50ct, in a claw-setting to a scalloped surround encrusted with single-cut diamonds, between tapered diamond-set shoulders leading to shank, testing as platinum on 18ct, ring head 1.8 x 1.4 cm, size K, 4.5 grams.

A verbal assessment of the Gemmological Certification Services confirms sapphire to be Sri Lankan (Ceylon) in origin, with no indications of heat treatment. Ref.: 5785-1697