Sapphire and diamond ring. Photo Tiancheng International.

Centring on a cushion-shaped cabochon sapphire weighing 43.17 carats, within double surrounds of brilliant-cut diamonds extending to a split shoulders, the diamonds together weighing 2.50 carats, mounted in 18 karat white gold. Ring size: 6 Estimate: HK$2,500,000 - 3,500,000 (US$320,000 - 450,000)

Accompanied by Gubélin report numbered 14037119, dated 5 March 2014, stating that the 43.17 carat sapphire is natural, Blue colour, of Burmese origin, with no indications of heating; also accompanied by GRS report numbered GRS2010-021278, dated 3 February 2010, stating that the 43.17 carat sapphire is natural, Vivid Blue colour (GRS type "Royal Blue"), of Burmese origin, with no indication of thermal treatment. Further accompanied by C. Dunaigre report numbered CDC 1205137, stating the 43.18 carat sapphire is natural, Intense Blue colour, of Burmese origin, with no indications of heating.

Tiancheng International. Jewelry and Jadeite.8 june 2014 - http://www.tianchengauction.com/