Borneo also yields diamonds. The stone known as the 'Matan' is said to have been found in 1787 in the Landak mines, near the west coast of Borneo. It is described as being an egg-shaped stone, indented on one side, and weighing, in its uncut state, 367 carats. Great doubt, however, exists as to the genuineness of this stone, and the Dutch experts who examined it a few years ago pronounced it to be simply rock-crystal. Among other diamond localities may be mentioned the Ural Mountains and several of the United States. The largest diamond yet recorded from North America was found at Manchester, Chesterfield county, Virginia. It weighed 23-3/4 carats, and yielded, when cut, a brilliant known as the 'Ou-i-nur,' which weighed, however, only 11-3/4 carats.
A few special diamonds, from their exceptional size or from the circumstances of their history, deserve notice. Of all the great diamonds, the 'Koh-i-nur' is perhaps the most interesting. While tradition carries it back to legendary times, it is known from history that the Sultan Ala-ed-din in 1304 acquired this gem on the defeat of the Rajah of Malwa, whose family had possessed it for many generations. In 1526 it passed by conquest to Humaiun, the son of Sultan Baber. When Aurungzebe subsequently possessed this stone, he used it as one of the eyes of the peacock adorning his famous peacock throne. On the conquest of Mohammed Shah by Nadir Shah in 1739, the great diamond was not found among the Delhi treasures, but learning that Mohammed carried it concealed in his turban, Nadir, on the grand ceremony of reinstating the Mogul emperor on the throne at the conclusion of peace, offered to exchange turbans, in token of reconciliation, and by this ruse obtained possession of the gem. It was when Nadir first saw the diamond on unfolding the turban, that he exclaimed 'Koh-i-nur,' or 'Mountain of Light,' the name by which the gem has ever since been known. At Nadir's death it passed to his unfortunate son, Shah Rokh, by whom it was ultimately given to Ahmed Shah, the founder of the Durani Afghan empire. By Ahmed it was bequeathed to his son, Taimur Shah; and from his descendants it passed, after a series of romantic incidents, to Runjit-Singh. On the death of Runjit, in 1839, the diamond was preserved in the treasury of Lahore, and on the annexation of the Punjab by the British in 1849, when the property of the state was confiscated to the East India Company, it was stipulated that the Koh-i-nur should be presented to the Queen of England. It was consequently taken in charge by Lord Dalhousie, who sent it to England in 1850. After the Great Exhibition of 1851, where it had been exhibited, it was injudiciously re-cut in London by Voorsanger, a skilful workman from Messrs Coster's factory at Amsterdam. The re-cutting occupied 38 days of 12 hours each, and the weight of the stone was reduced from 186-1/16 to 106-1/16 carats. The form is that of a shallow brilliant, too thin to display much fire. According to Lady Burton, it is believed to bring ill-luck to its possessor.