Lot 528. Spectacular 17.61 carats Colombian emerald and diamond ring. Estimate 420,000 — 610,000 CHF. Lot sold 494,500 CHF. Photo: Sotheby's 2012

The cushion-shaped emerald weighing 17.61 carats, set between trapeze diamond shoulders, the band partially set with brilliant-cut stones, size 52.

Accompanied by Gübelin report no. 12055200 and AGL report no. CS 49757, both stating that the emerald is of Colombian origin, with no indications of clarity modification.

Sotheby's. Magnificent Jewels, Geneva, 14 Nov 2012