An unmonted sapphire. Photo Christie's Image Ltd 2014.

The cushion-shaped sapphire weighing approximately 16.94 carats. Estimate CHF1,000,000 – CHF1,500,000 ($1,137,534 - $1,706,301)

Accompanied by report no. 73645 dated 20 March 2014 from the SSEF Swiss Gemmological Institute stating that the sapphire is of Kashmir origin, with no indications of heating, and an Appendix letter stating that the sapphire 'exhibits a remarkable size and weight of 16.949 ct combined with an attractive saturated blue colour and a fine purity.'

Report no. 14030251 dated 27 March 2014 from the Gübelin GemLab stating that the sapphire is of Kashmir origin, with no indications of heating, an Information Sheet on Unheated sapphires and an Appendix stating that the sapphire '..possesses a richly saturated and homogeneous colour, combined with a high degree of transparency, and a finely proportioned cut.' 

Christie's. GENEVA MAGNIFICENT JEWELS. 14 May 2014. Geneva -www.christies.com