Initially, the Golden Jubilee was a 755.5 carats large brown diamond. When the diamond was discovered in Premier Mines's prolific blue ground region, it did not attract significant media attention. Years later, the diamond was still largely hidden from the outside world. But in 1990, processing works on the diamond commenced. De Beers, the company that operated Premier Mines, oversaw the cutting process. However, there was one monumental challenge. The diamond featured a large surface and visible cracks from its inside. Besides, the numerous inclusions that the stone had affected its quality and difficulties presented in cutting it.
It was time for De Beers to explore some of the cutting-edge diamond-cutting tools and techniques the company had developed for years. These tools and methods were developed to cut the colorless, flawless, 273.85 carats D-color Centenary Diamond. Eventually, De Beers hired Gabriel Tolkowsky to help with the cutting work. It allowed Gabriel Tolkowsky to test these techniques and prove their viability.
The many cracks and inclusions in the diamond made it hard to cut the stone in the open due to lighting and vibration challenges. An idea to construct an underground room was deliberated. The room was free from vibrations, making it easier to control the lighting conditions.
In 1990, the stone was successfully reduced to 545.65 carats, down from the original 755.50 carats. Upon cutting the Golden Jubilee Diamond, Mr. Tolkowsky described the cut as a “Fire-Rose cushion shape.”
The Thai Diamond Manufacturers Association then brought the diamond to Thailand for display at the Thai Board of Investment Exhibition in Laem Chabang. The diamond was chosen to mark the centennial celebrations of De Beers in 1988.
In 1995, a group of Thai investors led by Henry Ho purchased the diamond from De Beers. Henry Ho was not only fascinated by the fire and brilliance of this gem; he also observed that it was quite heavy. In an interview with the Natural Color Diamond Association, Henry Ho compared the size of the diamond to two chickens. Therefore, a lot more to the diamond made investing in it worth the risk.
Arrangements were made for the gem to be offered to King Bhumibol as a gift from his subjects. The king was due to celebrate the 50th anniversary of his ascent to the throne, which is how the diamond earned the name Golden Jubilee.
In 2000, the King’s daughter, Princess Maha Chakri Sirindhorn, received the diamond on her father’s behalf. The Thai government had gone through years of economic austerity when purchasing the diamond. Citizens were very conscious of the government’s spending policies. A massive investment like this, whose value was more sentimental than practical, would raise a few questions. Therefore, information on the actual cost of the Golden Jubilee Diamond was largely unavailable. At some point, the Thai government reported the diamond as a large topaz to keep its real value secret.
The Golden Jubilee Diamond is presently on display at the Royal Museum, located within the Pimammek Golden Temple Throne.