A single strand natural pearl and diamond necklace. Estimate CHF430,000 – CHF520,000 ($438,869 - $530,725). Photo Christie's Image Ltd 2015

Composed of one hundred and ninety-four graduated natural pearls, measuring approximately 11.65 to 6.90 mm, to the circular and baguette-cut diamond tonneau-shaped clasp, 144.0 cm

Accompanied by report no. 82023 dated 17 September 2015 from the SSEF Swiss Gemmological Institute stating that 192 pearls are saltwater natural pearls, and that 2 are freshwater natural pearls. 

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