An emerald and diamond pendant necklace, by Harry Winston. Photo Christie's Image Ltd 2013

Suspending a detachable pendant set with a pear-shaped emerald, weighing approximately 30.19 carats, within a circular and pear-shaped diamond surround, to the graduated circular-cut diamond neckchain, mounted in platinum and gold, 14 ins. Pendant with maker's mark for Harry Winston, neckchain signed Winston for Harry Winston. Estimate $350,000 – $500,000

With report 12105130 dated 29 October 2012 from Gübelin Gem Lab stating that gemmological testing revealed characteristics consistent with those of emeralds originating from Colombia. Indications of minor clarity enhancement

Christie's. NEW YORK MAGNIFICENT JEWELS AND THE PRINCIE DIAMOND. 16 April 2013. New York, Rockefeller Plaza.