Important  ruby and diamond ring. Photo Sotheby's

The cushion-shaped ruby weighing 11.01 carats, claw-set between baguette diamond shoulders, size 52. Estimate:  750,000 – 1,125,000 CHF

Accompanied by SSEF report no. 60569 and GRS report no. GRS2011-091719, each stating that the ruby is of Burmese origin, with no indications of heating, the GRS report adding that testing revealed characteristics corresponding to those of a natural ruby from the Mogok region, demonstrating a rare combination of size and fine colour, spared of thermal treatment.

Sotheby's. Magnificent Jewels and Noble Jewels. Genève | 14 mai 2013, www.sothebys.com