Alexander Calder necklace to see $300,000 at Christie's

A necklace designed by US sculptor Alexander Calder (1898-1976) will see some of the highest bids at Christie's First Open Sale of Post War and Contemporary Art, having been bought at a flea market for just $15.

The necklace has been authenticated by the Calder Foundation

The necklace, a spiralled brass piece made in 1938, will now sell with a $200,000-300,000 estimate as one of the highest valued lots of the sale on September 26.

The necklace was found in 2005, lying in a box on the street at the famous Brooklyn Flea in New York.

It wasn't until three years later that its purchaser, a self-proclaimed "flea market junkie", saw an advert for the Philadelphia Art Museum's exhibit Calder Jewellery.

Her friend pointed out the similarity to the necklace that she had bought some years earlier and persuaded her to show it to the Calder Foundation in New York, where it was given an archive registration number to confirm its authenticity.

Christie's currently holds the record for any piece of Calder's work (Lily of Force, $18.5m, 2012), as well as the record for his outdoor sculptures, hanging mobiles, standing mobiles and jewellery, which was set by a 1939 necklace in 2011 at $602,500.

Sotheby's opened its selling exhibition dedicated to Calder's works on paper in New York yesterday (August 15).

The necklace will be joined by an important ink and gouache work by Mark Rothko, which also holds a $200,000-300,000 estimate.

The untitled work, unseen on the market for 20 years, reflects Rothko's little known surrealist influences, featuring biomorphic forms typical of the movement that dominated mid-century art.