The De Beers Millennium Star is, at 203.04-carat (40.608 g), the world’s largest top colour (D), internally and externally flawless, pear-shaped diamond.

The diamond was discovered in the Mbuji-Mayi district of Zaire (Republic of the Congo) in 1990 in alluvial deposits, uncut it was 777-carat (155.4 g). It was purchased by De Beers. It took over three years for workers of the Steinmetz Diamond Group to produce the classic pear form; the actual cutting was done using lasers.

It was first displayed in October 1999 as the centerpiece of the De Beers Millennium diamond collection. The collection also includes eleven blue diamonds totaling 118 carats (23.6 g) and the 27.64 carat (5.528 g) heart-shaped stone named the Heart of Eternity. They were displayed at London’s Millennium Dome over 2000. There was an attempt on November 7, 2000 to steal the collection.

The largest cut white (D) diamond by weight is the 1991 heart-shaped 273.85 carat (54.77 g) Centenary diamond .