An emerald and diamond ring, by David Webb. Photo Christie's Image Ltd 2014

Of bombé design, set with an oval cabochon emerald, within a tapered baguette and circular-cut diamond surround, mounted in platinum. Signed David Webb, no. AA862. Estimate $20,000 – $30,000

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