Multi-coloured natural pearl and diamond necklace. Photo: Sotheby's.

The double-stranded necklace composed of one hundred and ninety graduated natural pearls measuring approximately 8.45 to 3.30mm, each spaced by a faceted diamond bead, completed by a clasp set with button-shaped natural pearl measuring approximately 8.65 x 8.55mm, surrounded by circular-cut diamonds, mounted in silver-topped gold, length approximately 520mm. Estimation 650,000 — 750,000

Accompanied by SSEF report numbered 69075, dated 12 July 2013, stating that the pearls are natural saltwater pearls, with no indications of artificial colour modification. The pearl on the clasp has not been tested. 

Sotheby's. Magnificent Jewels and Jadeite. Hong Kong | 07 oct. 2013 - http://www.sothebys.com