Heart of Eternity Diamond

The Heart of Eternity is a diamond measuring 27.64 carats (5.528 g), rated in color as "Fancy Vivid Blue" by the Gemological Institute of America. The Heart of Eternity was cut by the Steinmetz group, who owned the diamond before selling it to the De Beers Group.

The Heart of Eternity is a member of an exceedingly rare class of colored diamonds. It was found in the Premier Diamond Mine of South Africa. Blue diamonds account for less than 0.1% of the output of the Premier mine,^{[citation needed]} which is the only mine in the world with an appreciable production of blue diamonds. Of the ten colored diamonds that drew the highest bids, six of those ten were blue diamonds, rating values as high as $550,000 to $580,000 per carat ($2750–2900/mg).

The original gem from which the Heart of Eternity came weighed 777 carats (155 g), which was considered to be a magical number, and set off a "gold rush" for similar gems. The cutting of the rough stone was planned for four to five months, until it was decided the rough gem would be cut into three pieces. The largest piece became the Millennium Star, and another part of the gem became the Heart of Eternity Diamond.

The Heart of Eternity was unveiled in January 2000 as part of the De Beers Millennium Jewels collection, which included the Millennium Star. The Heart of Eternity was featured with ten other blue diamonds; the collection of blue diamonds totaled 118 carats (23.6 g). The De Beers Millennium Jewels were displayed at London’s Millennium Dome throughout 2000. An attempt on November 7, 2000 to steal the collection was foiled.

During its exhibition at the Smithsonian, the Heart of Eternity was noted to be on loan from a private collector, giving rise to speculation that it was sold sometime during the exhibition at the Millennium Dome in London.