A Diamond Ring, by Van Cleef & Arpels. Photo: Christie's Images Ltd 2012

Set with a pear-shaped diamond, weighing approximately 16.33 carats, flanked on either side by a tapered baguette-cut diamond, mounted in platinum. Signed V.C.A. for Van Cleef & Arpels, N.Y., no. 45089. Estimate $1,850,000 - $2,500,000

With report 1142269599 dated 21 December 2011 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. Magnificent Jewels, 17 April 2012, New York, Rockefeller Plaza