The Cullinan diamond was found by a miner named Thomas Evan Powell, who brought it to the surface and gave it to Frederick Wells, surface manager of the Premier Diamond Mining Company in Cullinan, South Africa, on 26 January 1905.
- 1⁄3 pounds (600 grams), 3
- 7⁄8 inches (98 mm) long, 2
- 1⁄4 inches (57 mm) wide and 2
5⁄8 inches (67 mm) high the diamond was twice the size of any previously discovered. Wells immediately took it for examination.
Sir William Crookes performed an analysis of the Cullinan diamond, ascertaining a weight of 3,106 carats (621.2 grams). The stone was immediately named after Sir Thomas Cullinan, the owner of the diamond mine, who had discovered the mine after many years of unsuccessful searching. Crookes mentioned its remarkable clarity, but also a black spot in the middle. The colours around the black spot were very vivid and changed as the analyser was turned. According to Crookes, this pointed to internal strain. Such strain is not uncommon in diamonds. Because one side of the diamond was perfectly smooth, it was concluded that the stone had originally been part of a much larger diamond, that had been broken up by natural forces. Crookes pronounced the Cullinan “a fragment, probably less than half, of a distorted octahedral crystal; the other portions still await discovery by some fortunate miner.” The discovery became a global sensation, with the developments being followed avidly by the press.
Wells was awarded £3,500 for the find and the diamond was purchased by the Transvaal Colony government for £150,000 and insured for ten times the amount. Prime Minister Louis Botha suggested that the diamond be presented to King Edward VII as “a token of the loyalty and attachment of the people of Transvaal to his throne and person”. A vote was staged in order for the government to find out what should be done with the diamond. In the aftermath of the Boer Wars the Boers voted in favour of presenting the king with the diamond and the English settlers voting against such a move. The final vote was 42 against and 19 in favour. In the wake of the vote, the British prime minister of the time, Henry Campbell-Bannerman, decided to leave the decision of whether to accept the gift up to the king himself. However, future prime minister Winston Churchill eventually managed to persuade the king to accept, to which Edward VII finally agreed. Churchill was presented with a replica of the diamond, which he allegedly delighted in showing off to friends and displaying on a silver plate.