Christie's is set to auction off an ultra-rare 14.6-carat blue diamond that is expected to sell for between $35 million and $45 million — though experts say it could top the high end of that range and set a new record for a blue stone.
The rock will be the largest fancy vivid blue diamond ever sold at auction and is a so-called rectangular cut — among the most prized in the diamond world. Its value is also enhanced by its previous owner. The diamond, called the "Oppenheimer Blue," was owned by Philip Oppenheimer, the late chairman of the De Beers diamond-marketing cartel.
"Here's a man who could have had any diamond in the world, and this is the blue diamond he chose to have," said Rahul Kadakia, Christie's head of jewelry. "This is the 'Mona Lisa' of blue stones."
In the diamond world, blue is one of the rarest and most sought-after colors. Kadakia said that less than 2 percent of diamonds discovered in the world are blue (the color comes from the presence of boron in the diamond). Only 10 percent of all blue diamonds discovered are larger than a carat — so the Oppenheimer Blue is a highly prized freak of nature. It also has the highest color rating of "vivid."