An emerald and diamond ring. Photo Christie's Image Ltd 2014

Set with an octagonal-cut emerald, weighing approximately 7.05 carats, to the half-moon diamond shoulders and micro-pavé diamond surround and gallery, mounted in gold, ring size 6. Estimate CHF28,000 – CHF45,000 ($31,935 - $51,324)

Accompanied by report no. 72686 dated 13 February 2014 from the SSEF Swiss Gemmological Institute stating that the emerald is of Colombian origin, with indications of moderate amount of artificial resin in fissures

Report no. GRS2010-111506 dated 9 November 2010 from the GRS GemResearch SwissLab stating that the emerald is of Colombian origin, with indications of moderate clarity enhancement