Lot 496. Property of Mary, Duchess of Roxburghe. Natural pearl and diamond necklace, circa 1920. Estimation 245,000 — 345,000 CHF. Lot sold 1,630,000 CHF. Photo Sotheby's. 

Composed of millegrain-set marquise-shaped and circular-cut diamonds, the front with garland and ribbon designs supporting seven oval and button shaped natural pearls measuring from approximately 11.40 x 11.50 x 9.90mm to 15.10 x 15.15 x 13.70mm, length approximately 360mm, case stamped Cartier, the exterior of the case with monogram and coronet for Mary, Duchess of Roxburghe..

Accompanied by SSEF report no. 79503, stating that the seven pearls were found to be natural, saltwater, with no indications of artificial colour modification.

Sotheby's. Magnificent Jewels and Noble Jewels, Genève, 12 mai 2015