A "mystery-set" ruby and diamond flower brooch, by Van Cleef & Arpels. Photo: Christie's Images Ltd 2014.

Designed as a calibré-cut ruby flower, centering upon a circular-cut diamond cluster pistil, extending a baguette-cut diamond stem and marquise-cut diamond leaves, mounted in platinum, in a Van Cleef & Arpels blue suede box. Signed Van Cleef & Arpels, N.Y., no. 59545. Estimate: $100,000 – $150,000

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