The foremost gem in the history of the diamond was that which was called the Great Mogul. This was the largest of all known diamonds, and was found in the rich mines of Gani about the year 1650, or nearly a century after their discovery. It became the property of Vizier Mirgimola, who, although a Persian by birth, had by ability and tact risen to the honor of general and vizier to the King of Golconda. By means of his rapacity in war, and his success in working the diamond mines, he became enormously wealthy, and accumulated immense numbers of gems. The King finally became jealous of the wealth and power of his favorite, and resolved to destroy him. But Mirgimola, warned of his danger in time, succeeded in escaping with all his treasures to the capital of Shah Jehan, the Great Mogul. The wily Persian gained the favor and protection of the Hindoo monarch by magnificent presents of gems, the chief of which was the immense diamond which has since been called the Great Mogul. The original weight of this mammoth gem is said to have been 787¹⁄₂ karats; but during the process of cutting it was reduced to 279 karats. Tavernier relates that the work had been intrusted to a Venetian lapidary by the name of Hortensio Borghis, who, ignorant of the duties of his task, removed the flaws and external imperfections by grinding the surface of the stone away. The labor required by this operation seems almost incredible when we come to consider the hardness of the stone, and estimate the difficulty of polishing it, especially with the rude means then in use by the Oriental lapidaries. The cutting of the Pitt diamond (now the Regent) required two years’ time, with the aid of modern appliances and the facilities afforded by means of cleavage, by which large fragments were removed and utilized. Therefore the statement that this stone was reduced solely by grinding from 787¹⁄₂ karats to 279 karats is likely to meet with disbelief among the lapidaries; for the operation must have required more than the fifteen years which had elapsed from the discovery of the gem to the time Tavernier examined it. Tavernier says distinctly that cleavage was not resorted to in facilitating the reduction of the stone. We quote: “Had the Sieur Hortensio been well acquainted with his profession he might have obtained from this great stone some good pieces without doing any injury to the King, and without having taken so much trouble in grinding it away; but he was not a very skilful diamond-cutter.” This statement establishes the fact that the secret of reducing diamonds by cleavage was known at that time.