A sapphire and diamond necklace, by Cartier. Photo Christie's Image Ltd 2014

Suspending a fringe of cushion and oval-cut sapphires, each within a variously-cut diamond surround, to the line of oval-cut sapphires of similar design, intersected by baguette-cut diamond scrolling detail, 15 ins. Signed Cartier, nos. 934241 and 860243. Estimate $150,000 – $200,000

With report CS 59827 dated 13 March 2014 from the American Gemological Laboratories stating that it is the opinion of the Laboratory that of the sixteen sapphires, an excess of 50 were tested at random; the majority would be classified as Thailand - Cambodia (Pailin), two as Burma and one as Ceylon, all tested sapphires show no gemological evidence of heat

Christie's. MAGNIFICENT JEWELS, 16 April 2014, New York, Rockefeller Plaza - www.christies.com