Sapphire ring. Photo Sotheby's

Set with a step-cut sapphire weighing 16.58 carats, size 52.  Lot 368. Estimate 92,000-142,000 CHF

Accompanied by Gubelin report no. 12030108, stating that the sapphire is of Burmese origin, 'Royal Blue' colour, with no indications of heating.

Sotheby's. Magnificent Jewels and Noble Jewels. Genève | 14 mai 2012, 11:00 AM www.sothebys.com