Today in 1905, the largest diamond ever discovered was mined in Pretoria, South Africa. The diamond, a 3,106-carat specimen, was noticed by a miner and initially discarded by his supervisor as a piece of worthless crystal. The rock is enormous. It weighs a full 1.33 pounds and is nicknamed the "Cullinan."
Having retrieved the diamond from the mine, Wells delivered it to the mine's owner, Sir Thomas Cullinan. Cullinan sold it to the Transvaal government, who in turn gifted it to King Edward VII on his birthday.
King Edward, paranoid that his diamond would be stolen while in transit to him, had a fake sent at the same time, on a steam ship bristling with detectives. The tactic worked and the real diamond made its way back to the UK. It was entrusted to a stone cutter named Joseph Asscher, the same man who cut the Excelsior Diamond. Asscher took a full six months to prepare before making his first cut on the Cullinan.
Diamond is extremely hard. The Cullinan broke Cullinan's steel blade on his first cut. The second try saw the rock break in exactly the way Asscher had intended it to. Asscher, driven to the brink by the pressure of the moment, fainted.
Surprisingly, the enormous diamond was not allowed to remain enormous. It was divided into nine large stones and 98 smaller ones. The largest specimen, called the "Star of Africa I" or "Cullinan I," is the world's largest fine-quality colorless diamond. The world's second largest also came from the original Cullinan, called the "Star of Africa II" or "Cullinan II," and is 317 carats to Star of Africa's 530 carats.
Cullinans I, II and III are all on display at the Tower of London, along with the other crown jewels. Cullinan I was mounted to the British Sovereign's Royal Scepter and the Cullinan II was mounted to the Imperial State Crown.
This video will give you a sense of just how large the gems are.