Sotheby’s unveils a diamond unlike any offered before: an extraordinary 100-carat perfect diamond in a classic Emerald-cut. The remarkable 100.20-carat, D color, Internally Flawless, Type IIa stone will highlight Sotheby’s Magnificent Jewels auction in New York on 21 April 2015, when it is estimated to sell for US$19-25 million. At this scale, diamonds of this exceptional quality – D color and Internally Flawless clarity – are incredibly rare, and are considered “perfect”. The present example joins an elite group of just five comparable-quality diamonds over 100 carats that have ever been sold at auction worldwide.