An Important Sapphire and Diamond Ring. Photo: Christie's Images Ltd 2013

Set with a cushion-cut sapphire, weighing approximately 15.88 carats, flanked on either side by a half moon diamond, mounted in 18k white gold. Estimate:  $1,200,000 – $1,500,000

With report CS 82684 dated 14 March 2013 from the American Gemological Laboratories stating that it is the opinion of the Laboratory that the origin of the sapphire would be classified as Kashmir. No gemological evidence of heat

With report 67061 dated 12 March 2013 from SSEF Swiss Gemmological Institute stating that the analysed properties confirm the authenticity of the sapphire. Origin: Kashmir. No indications of heating

Christie's. MAGNIFICENT JEWELS. 15 October 2013. New York, Rockefeller Plaza.