A Fancy Yellow Diamond Ring by David Webb. Photo: Christie's Images Ltd 2012

Of bombé design, set with a round-cornered modified rectangular-cut fancy vivid yellow diamond, weighing approximately 39.83 carats, to the circular-cut diamond surround, gallery and shoulders, mounted in 18k gold. Signed David Webb - Lot 58. Estimate $1,200,000 - $1,800,000

With report 14611602 dated 12 April 2012 from the Gemological Institute of America stating that the diamond is fancy vivid yellow, natural color, VS1 clarity 

Christie's. New York Important Jewels. 12 June 2012. New York, Rockefeller Plaza 

“Fancy vivid yellow is the strongest color saturation for yellow diamonds and it is extremely rare to find examples of almost 40 carats. This impressive David Webb creation is part of an important private collection and no doubt one of the stars of our June auction.” – Rahul Kadakia, Head of Jewelry Department