A multi-colored sapphire bead necklace, by Tamzen Z, Ann Ziff. Photo Christie's Image Ltd 2014

Designed as a multi-strand torsade, with multi-colored faceted sapphire beads, joined by a circular-cut yellow sapphire clasp, mounted in gold, in a Tamsen Z purple suede case. By Tamzen Z, Ann Ziff. Estimate $15,000 – $20,000

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