An impressive 80.73 carats cushion-cut diamond ring. Estimate $4,000,000 – $5,000,000. Photo Christie's Image Ltd 2015

Set with a cushion-cut diamond, weighing approximately 80.73 carats, mounted in platinum

With report 1162934289 dated 9 February 2015 from the Gemological Institute of America stating that the diamond is K color, VS2 clarity, with excellent polish and excellent symmetry 

Christie's. MAGNIFICENT JEWELS, 14 April 2015, New York, Rockefeller Plaza