Weighing 14.62 carats, the Oppenheimer Blue will be the largest vivid blue diamond ever to appear at auction - and is estimated to be worth between $34m (£24m) and $45m.
The stone will lead Christie’s auction of Magnificent Jewels, held at the Four Seasons Hotel des Bergues in Geneva on 18 May.
"The Oppenheimer Blue can only be described as one of the rarest gems in the world," said Christie's Asia Pacific and China chairman, Francois Curiel. "It is the gem of gems."
The stunning sparkler is named after its previous owner, diamond aficionado Sir Philip Oppenheimer, who made his fortune with the De Beers mining group.
"The Oppenheimers have been leaders in the diamond industry for generations and Sir Philip could have had any diamond he wanted," said Curiel. "But he chose this one, with its perfect hue, impeccable proportions and fabulous rectangular shape."
According to Curiel, blue diamonds are gaining more popularity: "Blue diamonds have gained a wider following, not only because they are stunning, but because there are so few of them available in the world."