Seven stones cut from the Cullinan Diamond will go on display as part of the Queen's Diamond Jubilee. The stones are set in a ring, a necklace, and brooches which have been worn by the Queen during various times in her sixty-year reign.

The Cullinan Diamond was discovered in a South African mine in 1905 and weighed a whopping 3,106 carats in its rough state. It was named after Thomas Cullinan, the chairman of the mining company.

The exhibit will take place from June 30-July 8, and then from July 31-October 7 in Buckingham Palace. The exhibit will also display some of the Queen’s personal jewels and show how they have been used by British monarchs over the past 200 years.

"So incredible was its discovery that the moment it was found at the Premier Mine it was thrown out of the window of the mine manager's office because it was thought to be a worthless crystal,” said exhibition curator Caroline de Guitau, who also said that prior to the discovery of the Cullinan diamond, a diamond of that size had never been seen—the Cullinan diamond was originally 10.1 cm high.

The stone was sent to London after its discovery but remained uncut for some years because buyers did not know how it could be cut. In 1907 the stone was eventually cut into nine principal stones, as well as smaller stones and unpolished fragments, by IJ Asscher of Amsterdam.

The two largest stones are incorporated into the Crown Jewels—one in the sceptre and one in the Imperial State Crown.