An important sapphire and diamond pendant necklace. Photo Christie's Image Ltd 2013.

Suspending a cushion-cut sapphire, weighing approximately 91.38 carats, from horizontally-set graduated baguette-cut diamonds, to the baguette-cut diamondneckchain, joined by a circular-cut diamond clasp, mounted in 18k white gold. Estimate: $800,000 – $1,200,000

With report CS 81948 dated 25 September 2013 from the American Gemological Laboratories stating that it is of the opinion of the Laboratory that the origin of the sapphire would be classified as Burma (Myanmar). Heat Enhancement: None.

With report 71001 dated 8 September 2013 from the SSEF Swiss Gemmological Institute stating that the analysed properties confirm the authenticity of the transparent sapphire. No indications of heating. Origin: Burma (Myanmar). Accompanied by a supplemental letter from the SSEF Swiss Gemmological Institute attesting to the rarity and prestige of the sapphire. 

Christie's. MAGNIFICENT JEWELS. 10 December 2013. New York, Rockefeller Plaza -www.christies.com