A magnificent diamond ring by Taffin. Photo Christie's Image Ltd 2014

Set with a rectangular-cut diamond, weighing approximately 20.08 carats, to the pavé-set diamond mounting and hoop, mounted in platinum, size 7½, with maker's mark. Signed Taffin, no. 595. Estimate $2,400,000 – $3,200,000

With report 10665231 dated 21 March 2014 from the Gemological Institute of America stating that the diamond is D color, VVS1 clarity; accompanied by a working diagram indicating that the clarity may be potentially internally flawless

Accompanied by a supplemental letter from the Gemological Institute of America stating that the diamond has been determined to be a Type IIa diamond. Type IIa diamonds are the most chemically pure type of diamond and often have exceptional optical transparency. Type IIa diamonds were first identified as originating from India (particularly from the Golconda region) but have since been recovered in all major diamond-producing regions of the world. Among famous gem diamonds, the 530.20 carat Cullinan I and the 105.60 carat Koh-i-noor, are examples of Type IIa

Christie's. IMPORTANT JEWELS, 10 June 2014, New York, Rockefeller Plaza - http://www.christies.com/