A yellow sapphire and diamond ring. Photo Christie's Image Ltd 2014

Set with a rectangular-cut yellow sapphire, weighing approximately 31.86 carats, to the baguette-cut diamond shoulders, mounted in 18k white gold. Estimate $20,000 – $30,000

With report CS 60445 dated 15 April 2014 from the American Gemological Laboratories stating it is the opinion of the Laboratory that the origin of this yellow sapphire would be classified as Classic Ceylon (Sri Lanka). Heat enhancement: None

Christie's. IMPORTANT JEWELS,10 June 2014, New York, Rockefeller Plazahttp://www.christies.com/