A cushion and oval-cut Cambodia, Kashmir and Burma sapphire and diamond necklace, by Van Cleef & Arpels. Estimate $300,000 – $500,000. Photo Christie's Image Ltd 2015

Designed as a graduated series of eleven cushion and oval-cut sapphires and circular-cut diamond clusters, centering upon a cushion-cut sapphire, weighing approximately 7.02 carats, spaced by marquise and circular-cut diamond links to the marquise and circular-cut diamond backchain, mounted in platinum, 14½ ins., may also be worn as two bracelets of 7 ins. and 7½ ins., in a Van Cleef & Arpels green suede envelope pouch. Signed V.C.A., for Van Cleef & Arpels, N.Y., nos. 24943 and 24912

With report CS 64662 dated 1 December 2014 from the American Gemological Laboratories stating that it is the opinion of the Laboratory that the origin of these sapphires would be classified as a combination of 3 sapphires from Cambodia, 3 sapphires from Kashmir and 5 sapphires from Burma. No gemological evidence of heat. Clarity Enhancement: None

With report 14120106 dated 16 December 2014 from the Gübelin Gem Lab stating that gemmological testing of the sapphire, weighing approximately 7.02 carats revealed characteristics consistent with those of sapphires originating from Kashmir. No indications of heating

Christie's. MAGNIFICENT JEWELS, 14 April 2015, New York, Rockefeller Plaza