Lot 316. 23.88 carats Burmese step-cut sapphire and diamond ring. Estimate 330,000 — 550,000 CHF. Photo Sotheby's

Set with a step-cut sapphire weighing 23.88 carats, between shield-shaped diamond shoulders, size 501/2, Italian maker's mark.   

Accompanied by Gübelin report no. 1007245, dated 28 July 2010, stating that the sapphire is of Burmese origin, with no indications of heating, 'royal blue' colour, together with an appendix letter. 

Sotheby's. Magnificent Jewels and Noble Jewels, Genève, 16 nov. 2016, 10:30 AM