Christie's Geneva will present ''The Orange,'' a rare pear-shaped,14.82-carat, VS1, type IIa, vivid orange diamond at its magnificent jewels sale on November 12. The diamond has a presale estimate of $17 million to $20 million. The Gemological institute of America (GIA) noted that strongly colored diamonds in the orange hue range seldom exceed three or four carats once they are polished.
Pure orange diamonds are known as fire diamonds, as named by renowned gemologist Edwin Streeter in 1882.The are extremely rare in nature.
The largest orange diamond to be sold at auction to date was ''The Pumpkin Diamond,'' a 5.54-carat diamond that fetched $1.3 million at Sotheby's in 1997 when it was sold to Ronald Winston, of Harry Winston Inc.