A diamond and black diamond necklace. Photo: Christie's Images Ltd. 2011

Set at the front with a series of five heart, circular, rectangular, oval and pear-shaped black diamonds, spaced by circular-cut diamonds flanked by marquise-cut diamond florets, to the circular-cut diamond backchain and marquise-cut diamond clasp, mounted in platinum, 17 ins.  Estimate $40,000 - $60,000 - Price Realised $57,500

Christies's. Important Jewels, 14 June 2011, New York, Rockefeller Plaza www.christies.com