Ring; Yellow Sapphire & Diamond Three Stone in 18ct Gold & Platinum.
A certificated  natural (unheated) octagonal shaped neon yellow sapphire, 0.78ct, 4 claw set in yellow gold.
2 crisscut diamonds, 0.57cts FVS, 4 claw set in indivdual platinum collets. Yellow gold wed-fit band. Coronation Hallmark.
Made in England.

GFCO Gem Lab Report.