Gold, silver, sapphire bead and ruby necklace, René Boivin, France. Photo: Sotheby's.

The front composed of six strands of round sapphire beads graduating in size, spaced at intervals by links set with 54 cabochon rubies, completed by a semi-flexible collar of twisted design, internal circumference 13½ inches, with French assay and maker's mark; circa 1935. Estimation 25,000 — 35,000 USD 

THE COLLECTION OF ALEX & ELISABETH LEWYT

For a necklace of similar design, see René Boivin: Joaillier, by Françoise Cailles, pages 213.

Sotheby's. Important Jewels. New York | 24 sept. 2013 - http://www.sothebys.com