A coloured sapphire and diamond ring. Photo Christie's Image Ltd 2014

Set with an oval-shaped pink sapphire, weighing approximately 13.06 carats, to the pavé-set diamond gallery and graduated french-cut diamonds shoulders, mounted in platinum, ring size 6. Estimate CHF110,000 – CHF140,000 ($125,459 - $159,676)

Accompanied by report no. 71136 dated 3 October 2013 from the SSEF Swiss Gemmological Institute stating that the sapphire is a natural pink sapphire, with no indications of heating

Report no. GRs2013-0715564 dated 16 July 2013 from the GRS GemResearch Swisslab stating that the sapphire is a natural pink sapphire of Ceylon origin, with no indications of heating

Christie's. GENEVA MAGNIFICENT JEWELS. 14 May 2014, Geneva- http://www.christies.com/