Lot 261. 9.93 carats Kashmir step-cut sapphire and diamond ring. Estimate 470,000 — 590,000 CHF. Photo Sotheby's

Set with a step-cut sapphire weighing 9.93 carats, between baguette diamond shoulders, size 54, French import mark.  

Accompanied by SSEF report no. 85976 and Gübelin report no. 16070070, each stating that the sapphire is of Kashmir origin, with no indications of heating.

Note"Since their discovery in 1881, the legendary sapphire deposits of Kashmir have acquired a reputation based on a mixture of fact and fantasy that is usually associated with the ancient gem mines of the world. [The locality is] situated in the high Himalaya Mountains of northwest India and described in early reports as “the region beyond the snows”. (…) Few gemmologists would dispute that a fine Kashmir stone displays a character that sets it apart in a world relatively abundant in corundum gems. Over the years, the term Kashmir has come to signify the most desirable and expensive of blue sapphires". 

David Atkinson and Rustam Z. Kothavala, “Kashmir Sapphire”, in Gems & Gemology, Summer 1983, pgs. 64-76.

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