A sapphire and diamond cluster ring, the oval-cut sapphire weighing 13.16cts within a surround of

A sapphire and diamond cluster ring, the oval-cut sapphire weighing 13.16cts within a surround of pear-shaped and brilliant-cut diamonds in white gold, stamped 750, maker's mark JK, size N1/2

Accompanied by GCS report no. 5784-1700, dated 8th March 2024, and facsimile GRS report no. GRS2013-101694, dated 13th November 2013, both stating that the sapphire is of Myanmar (Burma) origin, with no evidence of heat treatment.