The brooch once belonged to Queen Mary, photo, wife of King George V, and is a treasure of the Queen
When the Cullinan diamond was mined in 1905, it only looked like a worthless crystal – so much that the manager of the Premier mine near Pretoria, South Africa, threw it away like a trash can.
It was only on closer inspection that the staff became convinced that the piece of rock could be a real diamond. In fact, it turned out to be three times larger than anything that had been discovered before.
Weighing 3,106 carats in the rough and measuring 4 inches by 2.5 inches by 2.12 inches, the Cullinan – named after the president of the mining company, Thomas Cullinan – was also exceptional for its blue-white color and its purity .
Shortly after his discovery, he was sent to Buckingham Palace for inspection by King Edward VII.
For two years, the stone remained a public wonder, but it was difficult to find a buyer because there were doubts that such a large stone could ever be cut.
Finally, the Prime Minister of the Transvaal – then a British colony – suggested that his government should acquire the Cullinan and present it to Edward VII as a sign of loyalty. In 1907, the uncut stone was brought to Sandringham House in Norfolk.
The brooch features gems cut from the Cullinan diamond, shown, which was mined in 1905. The total weight of the gems cut from Cullinan was 1,055.8 carats
The cutting of the stone was entrusted to the famous firm IJ Asscher of Amsterdam. It was too large to be cut into a single piece of jewelry, so cleavage – or sawing – was necessary.
The first hit broke the knife and the diamond remained intact. A second attempt cut him in half.
Eight months of grinding and polishing followed, resulting in nine main numbered stones, 96 small brilliants and nine carats of unpolished fragments.
The total weight of gemstones cut in Cullinan was 1,055.8 carats.