Natural pearl and diamond necklace. Estimation 3,000 — 5,000 GBP. Photo Sotheby's.

Designed as two gently graduated rows of natural pearls measuring from approximately 3.0 to 6.2mm, the clasp millegrain-set with circular-cut diamonds, length of shortest row approximately 380mm, French assay and indistinct maker's mark. 

Accompanied by the Gem & Pearl Laboratory report no. 10720, stating that the majority of the pearls were found to be natural saltwater and one was found to be a bead-nucleated cultured pearl.

Sotheby's. Fine Jewels, Londres, 18 mars 2015, 10:30 AM