A three-strand natural pearl and diamond necklace, by Bulgari. Price Realized CHF483,750 ($499,875). Photo Christie's Image Ltd 2013

Composed of sixty-three, sixty-seven and sixty-nine natural pearls, measuring approximately 8.1 to 5.1 mm, to the baguette and brilliant-cut diamond clasp centering upon a pearl measuring approximately 8.3 mm, mounted in platinum and gold, 1930s, 47.5 cm/ Clasp signed Bulgari, no. 13491 - Estimate CHF290,000 - CHF480,000 ($305,148 - $505,072)

Accompanied by report no. 67347 dated 21 March 2013 from the SSEF Swiss Gemmological Institute stating that 199 pearls are natural saltwater pearls

Please note that due to the setting, the pearl on the clasp has not been tested 

CHRISTIE'S. MAGNIFICENT JEWELS, 15 May 2013, Geneva