Tavernier, the French Traveller, saw in the possession of the Great Mogul a diamond which weighed near 280 carats. In form and size it resembled half a hen’s egg. This diamond had been obtained from the mine of Coulour, about the year 1550; and was valued at more than 700,000_l._ sterling. The sceptre of the Emperor of Russia is adorned with an oriental diamond about the size of a pigeon’s egg, which weighs 195 carats. This diamond is said to have once been placed as the eye of an idol in Seringham, in the Carnatic. A grenadier, who had deserted from the French service in India, contrived to become one of the priests of the idol, in the hope of being able to steal this eye. He at length effected his purpose, and escaped with the diamond to Madras, where he sold it to the captain of a ship for a sum equal to 2,500_l._ of British money. It was afterwards transferred to a Jew for 18,000_l._ Coming into the hands of a Greek merchant, he offered it for sale at Amsterdam, in 1766; and the Russian Prince Orloff bought it for the Empress Catharine for about 90,000_l._ sterling, and an annuity of 4,000_l._ during the life of the person who sold it. The _Pitt_, or _Regent diamond_ (Pl. II, Fig. 10), which lately was set in the handle of the sword of state of Buonaparte, and is now possessed by the king of France, is a brilliant of the most beautiful kind, and weighs 136¾ carats. It was brought from India by Thomas Pitt, Esq. Governor of Fort George. Mr. Pitt has himself stated, respecting it, that, in December, 1701, whilst resident in Madras, several valuable stones, in a rough state, were brought to him for sale by an eminent diamond merchant. One of these, the diamond here spoken of, was so large that the merchant asked for it the sum of 85,000_l._ After much bargaining, Mr. Pitt purchased it for 20,400_l._ He afterwards sold it for 135,000_l._ to the Regent Duke of Orleans; and by him it was placed among the crown jewels of France. The _Pigot diamond_ weighs forty─seven and a half carats. This, which is an extremely fine stone, was disposed of by lottery, in 1800, for 22,000_l._; and is now in the possession of Messrs. Rundell and Bridge, jewellers in London. A large star, cross, and chain, worn on grand gala days by the Prince of Brazil, as Sovereign of the different Portuguese orders of knighthood, are each ornamented with a great number of magnificent diamonds, set in gold. The centre diamond of the star is alone valued at 800,000_l._ When the diamond is rubbed it will attract bits of straw, feathers, hairs, and other small objects; and if exposed to the rays of the sun, and immediately taken into a dark place, some diamonds will appear luminous. ZIRCON FAMILY. 51. _JARGOON is a gem usually of smoky yellow or brownish colour, and sometimes limpid: if placed upon any object, it exhibits of it a very distinct double image._