A natural pearl and diamond necklace. Estimate CHF380,000 – CHF480,000 ($387,838 - $489,900). Photo Christie's Image Ltd 2015

The five strands composed of ninety-seven, ninety-four, ninety-two, ninety and eighty-seven graduated natural pearls, measuring approximately 10.40 to 3.80 mm, to the diamond-set openwork clasp, 51.5 cm, mounted in gold

Accompanied by report no. 71896 dated 16 December 2013 from the SSEF Swiss Gemmological Institute stating that the 460 pearls are natural saltwater pearls 

Christie's. GENEVA MAGNIFICENT JEWELS, 10 November 2015, Geneva