The De Beers Centenary Diamond is a 273.85 carats D Color F Clarity modified heart shaped diamond. It was named the Centenary Diamond as it was presented in the rough for the De Beers Centennial celebration in May 1988. The Centenary Diamond was unveiled in its final, polished form in May 1991.
The Centenary Diamond was discovered as a rough diamond of 599 carats in the De Beers Premier mine in South Africa in July 1986, although it was only presented as part of the Centennial celebration in 1988. It is the third largest diamond ever recovered in the Premier mine.
Cutting and Polishing
Among top-color diamonds, the Centenary is surpassed in size by only the Cullinan I and the Cullinan II, the 2 largest stones cut from the Cullinan diamond.
One of the best diamond cutters in the world, Gabi Tolkowsky, was entrusted with the task of cutting and polishing the Centenary Diamond. The actual cutting and polishing work took place in a room specially designed underground room at the De Beers Diamond Research Laboratory in Johannesburg, South Africa. The room was specifically designed to account for factors like strength and stability so as to avoid any unnecessary mechanical vibration or temperature variation, to minimize any influences that might interfere with the cutting of the Centenary Diamond.
The first steps in the cutting process were done by hand so as to avoid any negative ramifications from heat or lasers that would affect the diamond. This step took an incredible 154 days to remove 20 carats from the rough diamond. After the primary work that was done, Tolkowsky and his assistants created an incredible 13 sketches of possible cuts for the diamond and presented them to the board of De Beers, which eventually decided a modified heart shape for the Centenary Diamond. It is said that they chose that shape, envisioning its position on the turban of a Sultan or a Maharaja.
The Final Result
The diamond was cut and polished over 2 years to yield 273.85 carats of internally flawless beauty. The resulting masterpiece was a modified heart shaped diamond, with D color and both internally and externally flawless, with a total of 247 facets, including 164 on the stone and 83 on the girdle. The Centenary diamond is the largest modern fancy cut diamond in the world, and the only one to combine old cutting methods with sophisticated, modern cutting technology.
Although the official value of the Centenary diamond is not known, because its current owner is not public knowledge in accordance with the De Beers policy of anonymity, it is known that the diamond was insured for $100 Million upon its unveiling in 1991. Despite our lack of knowledge as to the diamond's worth and whereabouts, if it surfaces in a country's Crown Jewels or in a Museum, and goes on auction, we would then be able to conclude the Centenary diamond's worth today.