Alexandrite and diamond ring, Jérémie Pauzié. Estimate 370,000 — 540,000 CHF. Photo: Sotheby's

Set with a cushion-shaped alexandrite weighing 23.75 carats, in a decorative mount set throughout with brilliant-cut diamonds, size 54, signed Jérémie Pauzié, French assay and maker's marks.

Accompanied by SSEF report no. 55437, dated 9 February 2010, stating that the alexandrite is of Ceylon origin, with no indications of treatment and with a strong colour change.

Sotheby's. Magnificent Jewels and Noble Jewels, Genève, 12 mai 2015, 10:30 AM