The Golden Jubilee Diamond was cut from a large brown diamond of 755.5 carats, found in the prolific blue ground of the Premier Mine in South Africa in 1985. First known as the “Unnamed Brown,” the Golden Jubilee was given to Gabriel Tolkowsky (below) by De Beers for the purpose of testing special tools and cutting methods that had been developed for use on the colorless D-color Centenary.
Known as Gabi, Tolkowsky was (born 1939) and 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. He seems like such an eccentric man, I would love to sit down with him and dig in to what I believe is probably a big brain full of wisdom and character.
Because of its deep cracks and several inclusions, the Golden Jubilee was cut in a specially designed underground room free from vibrations as they were being as careful as possible to achieve the objective. What happens is, when a diamond cutter is working on a diamond, grinding, and polishing away, the diamond can crack in half or several pieces.
Imagine the stress! You are always trying to have the largest diamond possible from the piece of rough you are working on.
The yellow-brown diamond was transformed into a fire rose cushion cut. Until 1990, the diamond remained largely unknown to the outside world, requiring two years to bring it to its current state.
The unnamed diamond was brought to Thailand by the Thai Diamond Manufacturers Association to be exhibited in the Thai Board of Investment Exhibition in Laem Chabang and was selected to herald De Beer’s centennial celebrations in 1988.
The Golden Jubilee was purchased from De Beers by a group led by Henry Ho in 1995. De Beers considered this as an opportunity to test new cutting technologies. The same technology used in cutting the Golden Jubilee diamond was later used in the cutting of the Centenary Diamond, a smaller (273.85 carats) flawless and colorless rough diamond.