Centenary Diamond
Encyclopedia
The De Beers
Centenary Diamond is, at 273.85 carats (54.8 g), the third-largest diamond to have been produced in the Premier Mine
. The Centenary Diamond is rated in color
as grade D color by the Gemological Institute of America
, which is the highest grade of colourless diamond and is internally and externally flawless. It was named the Centenary Diamond as it was presented in the rough for the Centennial Celebration of De Beers Consolidated Mines on May 11, 1988. The Centenary Diamond was unveiled in final form in May 1991.
was chosen to head the team responsible for cutting the Centenary Diamond, along with Geoff Woolett, Jim Nash and Dawie du Plessis, assisted by a specially picked group of engineers, electricians and security guards to facilitate in the work on Centenary Diamond.http://famousdiamonds.tripod.com/centenarydiamond.htmlhttp://famousdiamonds.tripod.com/tolkowskyletter.html There was a special room designed underground in the De Beers Diamond Research Laboratory in Johannesburg
, South Africa for the sole purpose of working on the Centenary Diamond with design specifications including strength and stability so as to preclude mechanical vibration and temperature variation to minimise any mitigating factor that might interfere with the cutting of the Centenary Diamond.
The initial efforts were done by hand rather than with a laser or saw so as not to heat or vibrate the diamond. After cutting and removing 50 carats (10 g) of cracked material over 154 days, the team was left with an egg-shaped gem of approximately 500 carats (100 g). Thirteen different designs were presented to the De Beers board, with a strong recommendation for what became the eventual modified heart-shaped design. The shape was described as, "Effectively, the Centenary Diamond is shaped like a heart-shape, but it does not have a groove. The image the team had in mind was a shape which would adorn the turban of a Sultan or a Maharaja."
, where it was displayed for a number of years. It is believed that De Beers no longer owns the Centenary, but the current owner is unknown. Gabi Tolkowsky
has said that he believes that the gem was sold in June 2008 to a previously unknown young (some sources quote an 18-year-old http://www.dailymail.co.uk/news/article-115852) entrepreneur, apparently of British/Israeli origin, living in the United States http://famousdiamonds.tripod.com/tolkowskyletter.html, although De Beers declines to comment, citing its anonymity policy.
De Beers
De Beers is a family of companies that dominate the diamond, diamond mining, diamond trading and industrial diamond manufacturing sectors. De Beers is active in every category of industrial diamond mining: open-pit, underground, large-scale alluvial, coastal and deep sea...
Centenary Diamond is, at 273.85 carats (54.8 g), the third-largest diamond to have been produced in the Premier Mine
Premier Mine
The Premier Mine is an underground diamond mine owned by Petra Diamonds. It is situated in the town of Cullinan, 40 kilometres east of Pretoria, Gauteng Province, South Africa. Established in 1902, it was renamed the Cullinan Diamond Mine in November 2003 in celebration of its centenary...
. The Centenary Diamond is rated in color
Diamond color
A chemically pure and structurally perfect diamond is perfectly transparent with no hue, or color. However, in reality almost no gem-sized natural diamonds are absolutely perfect. The color of a diamond may be affected by chemical impurities and/or structural defects in the crystal lattice...
as grade D color by the Gemological Institute of America
Gemological Institute of America
The Gemological Institute of America, or GIA, is a nonprofit institute dedicated to research and education in the field of gemology and the jewelry arts. Founded in 1931, GIA's mission is to protect all buyers and sellers of gemstones by setting and maintaining the standards used to evaluate...
, which is the highest grade of colourless diamond and is internally and externally flawless. It was named the Centenary Diamond as it was presented in the rough for the Centennial Celebration of De Beers Consolidated Mines on May 11, 1988. The Centenary Diamond was unveiled in final form in May 1991.
Discovery
The Centenary Diamond was discovered in the Premier Mine on 17 July 1986 using their X-ray imaging system. The original rough was 599 carats (119.8 g) and it was presented on 11 May 1988 in the Centennial Celebration of the De Beers Consolidated Mines. As then-chairman Julian Oglivie Thompson said, "We have recovered at the Premier Mine a diamond of 599 carats (119.8 g) which is perfect in color – indeed it is one of the largest top-color diamonds ever found. Naturally it will be called the Centenary Diamond."Cutting the Centenary
Cutting such an immense and valuable diamond required expertise and a considerable investment. Gabi TolkowskyGabi Tolkowsky
Gabriel S. "Gabi" Tolkowsky is one of the world's most renowned diamond cutters, the sixth generation of the Tolkowsky family to make his name in the trade. He is the great nephew of Marcel Tolkowsky, the father of the modern round brilliant diamond cut.-Family history:In the 1800s Abraham...
was chosen to head the team responsible for cutting the Centenary Diamond, along with Geoff Woolett, Jim Nash and Dawie du Plessis, assisted by a specially picked group of engineers, electricians and security guards to facilitate in the work on Centenary Diamond.http://famousdiamonds.tripod.com/centenarydiamond.htmlhttp://famousdiamonds.tripod.com/tolkowskyletter.html There was a special room designed underground in the De Beers Diamond Research Laboratory in Johannesburg
Johannesburg
Johannesburg also known as Jozi, Jo'burg or Egoli, is the largest city in South Africa, by population. Johannesburg is the provincial capital of Gauteng, the wealthiest province in South Africa, having the largest economy of any metropolitan region in Sub-Saharan Africa...
, South Africa for the sole purpose of working on the Centenary Diamond with design specifications including strength and stability so as to preclude mechanical vibration and temperature variation to minimise any mitigating factor that might interfere with the cutting of the Centenary Diamond.
The initial efforts were done by hand rather than with a laser or saw so as not to heat or vibrate the diamond. After cutting and removing 50 carats (10 g) of cracked material over 154 days, the team was left with an egg-shaped gem of approximately 500 carats (100 g). Thirteen different designs were presented to the De Beers board, with a strong recommendation for what became the eventual modified heart-shaped design. The shape was described as, "Effectively, the Centenary Diamond is shaped like a heart-shape, but it does not have a groove. The image the team had in mind was a shape which would adorn the turban of a Sultan or a Maharaja."
The statistics
The Centenary was completed in February 1991, weighing 273.85 carats (54.8 g) with its dimensions measuring 39.90 × 50.50 × 24.55 mm. The final gem had 247 facets: 164 on the pavilion and crown, and 83 on the girdle. While the stone has never been publicly appraised for value, it is known to have been insured at over US$100 million at the time of its unveiling in May 1991. The stone was loaned to the Tower of LondonTower of London
Her Majesty's Royal Palace and Fortress, more commonly known as the Tower of London, is a historic castle on the north bank of the River Thames in central London, England. It lies within the London Borough of Tower Hamlets, separated from the eastern edge of the City of London by the open space...
, where it was displayed for a number of years. It is believed that De Beers no longer owns the Centenary, but the current owner is unknown. Gabi Tolkowsky
Gabi Tolkowsky
Gabriel S. "Gabi" Tolkowsky is one of the world's most renowned diamond cutters, the sixth generation of the Tolkowsky family to make his name in the trade. He is the great nephew of Marcel Tolkowsky, the father of the modern round brilliant diamond cut.-Family history:In the 1800s Abraham...
has said that he believes that the gem was sold in June 2008 to a previously unknown young (some sources quote an 18-year-old http://www.dailymail.co.uk/news/article-115852) entrepreneur, apparently of British/Israeli origin, living in the United States http://famousdiamonds.tripod.com/tolkowskyletter.html, although De Beers declines to comment, citing its anonymity policy.