Lot 278. A Colombian emerald, Burmese sapphire and diamond necklace, by Jahan. Estimate CHF 400,000 - CHF 600,000. Price realised CHF 1,385,000. © Christie's Image Ltd 2015 

Designed as a tapered flexible band of brilliant-cut diamond lines, centering upon a rectangular-cut emerald, suspending a pear-shaped sapphire, within a brilliant-cut diamond cluster, mounted in gold, 42.5 cm. Signed Jahan.

Accompanied by report no. 78361 dated 2 September 2014 from the SSEF Swiss Gemmological Institute stating that the emerald is of Colombian origin, with indications of moderate amount of artificial resin and that the sapphire is of Burmese origin, with no indications of heating.  

Christie's. MAGNIFICENT JEWELS, 13 May 2015, Geneva.