<P> The Golden Jubilee Diamond (Thai: เพชร กา ญ จ นาภิ เษ ก) is the largest cut and faceted diamond in the world . It weighs 545.67 carats (109.13 g). It outweighs the Cullinan I by 15.37 carats (3.07 g). The Golden Jubilee Diamond was discovered in the Premier Mine, which is also the origin of the Cullinan diamond (1905) and other notables such as the Taylor--Burton (1966) and the Centenary (1986). Cullinan I, also known as the Great Star of Africa, had held the title of the largest cut and faceted diamond since 1908 . </P> <P> The Golden Jubilee Diamond was cut from a large brown diamond of 755.5 carats (151 g), 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 by De Beers for the purpose of testing special tools and cutting methods that had been developed for use on the colourless D - colour Centenary . </P> <P> Because of its deep cracks and several inclusions, the Golden Jubilee Diamond was cut in a specially designed underground room free from vibrations . The yellow - brown diamond was transformed through 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 . </P> <P> 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 . </P>

545-carat golden jubilee diamond the largest cut and faceted diamond in the world