Lot 379. Important diamond necklace, the centre supporting a briolette diamond weighing 20.30 carats, by Cartier. Estimate: £220,000 - £280,000. Courtesy Sotheby's.

The front composed of three rows set with square, brilliant-cut and baguette diamonds, the centre supporting a briolette diamond weighing 20.30 carats, to a necklace composed of links set with brilliant-cut diamonds and marquise diamond clasp,  length approximately 385mm, signed Cartier, numbered, French assay and maker's marks, fitted case stamped Cartier.