Lot 521. Important diamond necklace, Cartier. Estimate 335,000 — 525,000 CHF. Lot sold 410,500 CHF. Photo: Sotheby's 2012

The front designed as three tiers of brilliant-cut and baguette diamonds brought together at the centre with carré-cut stones, suspending a briolette diamond weighing 20.30 carats, the back designed as a row of brilliant-cut stones, the clasp set with a marquise-shaped diamond, length of shortest row approximately 400mm, signed Cartier Paris and numbered, French assay and maker's marks, case signed Cartier.

Accompanied by GIA report no. 2145896940, stating that the 20.30 carat diamond is W to X range Colour, SI1 Clarity.