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

Set with an oval-shaped ruby, weighing approximately 19.64 carats, to the pavé-set diamond surround and bifurcated shoulders, mounted in gold, ring size 6½. Estimate CHF360,000 – CHF540,000 ($409,479 - $614,218)

Accompanied by report no. 68360 dated 27 May 2013 from the SSEF Swiss Gemmological Institute stating that the ruby is of Burmese origin, with no indications of heating, and an Appendix indicating that 'A natural ruby from Burma of this quality and size is exceptional.'

Report no. GRS2013-051429T dated 30 May 2013 from the GRS GemResearch Swisslab stating that the ruby is of Burmese origin, with no indications of heating

Christie's. GENEVA MAGNIFICENT JEWELS. 14 May 2014. Geneva -www.christies.com