What is the world’s largest faceted diamond? If you ask most knowledgeable people, including those in the jewelry trade, the answer would be one of the diamonds cut from the enormous Cullinan diamond, the largest rough diamond ever discovered, at more than 3,100 carats.

Cullinan diamond

The largest polished gem from the Cullinan diamond is called the Cullinan I, also known as the Great Star of Africa. It weights 530.4 carats and is mounted in the Sceptre with the Cross, part of the Crown Jewels of the United Kingdom.

But contrary to much popular opinion, the Cullinan I is in fact not the largest faceted diamond in the world, though it held that position since 1908. The Cullinan I was eventually eclipsed by a lesser known diamond, now known as the Golden Jubilee. This diamond has a curious history that eventually became closely connected with the country of Thailand.

Golden Jubilee Diamond


The Golden Jubilee was discovered in the Premier Mine in South Africa in 1986, the same mine that yielded the enormous Cullinan diamond. In fact there were two notable diamonds discovered in the Premier Mine in 1986 — the other was a 273.85 carat diamond that was named the Centenary in honor of the De Beers centennial.

The Centenary was selected to commemorate the De Beers centennial because of its remarkable perfection — the stone was graded D color (the highest grade for colorless diamonds) and is entirely flawless. The Golden Jubilee was a different case altogether. It was originally called the “Unnamed Brown” and was given by De Beers to the famous diamond cutter Gabriel Tolkowsky in order to test special tools and cutting methods which had been developed to cut the Centenary diamond. Once he had experimented on the “Unnamed Brown” he would move on to cut the Centenary.

Gabriel Tolkowsky
gabriel-tolkowskyTo the surprise of the diamond world, Tolkowsky cut a stunning yellow brown diamond in what he called a “fire rose cushion cut” from the 755.50 carat “Unnamed Brown. The finished stone has a carat weight of 545.65, exceeding the Cullinan I by 15.37 carats. The diamond was eventually purchased in 1995 from De Beers by a group in Thailand led by Henry Ho. It was presented to King Bhumibol Adulyadej of Thailand in honor of the 50th anniversary of his coronation and named the Golden Jubilee. It is now part of the crown jewels of Thailand and resides in the Grand Palace in Bangkok