A most interesting historic diamond is that called the (Shah? given in 1829 by Prince Khusrau of Persia to Emperor Nicholas I to placate the tsar for the murder in Teheran of the Russian Ambassador. On polished faces of the crystal were engraved the names of Akbar Shah, Nisim Shah and Fath Ali Shah; the latter began his reign in 1797. The weight of the is 86 carats (88.19 metric carats).
The largest and finest brilliant in the world to-day is one cut from the great Cullinan crystal found in the Premier mine in the Transvaal in 1905, and which weighed in the rough 3,106 metric carats. This crystal was presented in 1907 by the Union of South Africa to King Edward VII, and was cut into several gems in Amsterdam in the following year. The largest of these, which outranks all other brilliants, is called (Star of South Africa)); its weight is 5302 metric carats. Another brilliant, from the same crystal, bears the name (Lesser Star of Africa? and weighs 3171/2 metric carats; this stone ranks second among the world's brilliants. Next to these in size, among the South African diamonds, is the (Jubilee? weighing 245 metric carats (239 of the older carats); before cutting it weighed 634 carats (650.81 metric carats). In 1893 the Jagersfontein mine supplied what was until then the largest diamond crystal ever found, the (Excelsior? of 995 2/5 metric carats (9691/2 of the older carats). This was cut up into 10 brilliants, ranging in weight from 13.87 to 68.70 metric carats. Another large African diamond is that called the (Victoria? weighing 4571/2 carats (469.88 metric carats) in the rough and 184.77 metric carats as a brilliant. It was purchased by the late Nizam of Hyderabad for $2,000,000. Still another noteworthy African diamond is the (Tiffany Yellow° found in the Kimberley mine in 1877. In the rough it weighed 280 of the older carats (287.43 metric carats) ; in its present brilliant form its weight is 128.51 metric carats.
The largest diamond crystal in the world, as the Cullinan has been divided into several pieces, would be that called the (Braganza? now in the Portuguese treasury, providing it were a genuine diamond; but grave doubts have been expressed in regard to this and it has not been shown for over one century. The stone comes from Brazil, and must have been found prior to 1746. Perhaps the fact that the Braganza
diamond was never submitted to expert exam ination has contributed as much as anything else to the conjecture that it may be only a topaz. According to description, the stone is of a pro nounced yellow shade, its form being oblong and rounded, with a depression on one side, but an illustration in the Gentleman's Magazine of 1754 shows a rounded egg-shaped stone, sug gesting an elongated rolled pebble; in other words a white tonaz nehble and not a diamond_ It weighs 1,680 carats (1,72&72meiric carats). The diamond brilliant Imown as the (Regent" of Portugal, found in Brazil in 1775, weighs 215 carats (221.25 metric carats). Next in size among Brazilian diamonds is the of the South? found by a negress in the river Baga gem in 1853. In the rough it weighed 261.37 metric carats, and when cut as a brilliant 128.83 metric carats (1253/3 of the older carats). It was sold to the Gaekwar of Baroda for $450,000.
From 1750 to 1870 the value of a diamond was fixed on a basis of the square of its weight; that is, a 1-carat stone was a 10 carat stone was worth-10x 10x 1 —$10,000, This was due to the fact that large stones were rare. But in the African mines, large stones are found, and the increase in value from one carat up is worth only a fraction more per carat than the carat weight would show. When brilliants are exceedingly minute the value per carat may be double that of stones weighing one-sixteenth to one-fourth carat each, owing to the difficulty of cutting. The term (first quality° signifies a stone absolutely white and free from all flaws and imperfections. Im perfections, even if slight, or a tint of un desirable colors, greatly lower the value of a diamond. Many are cut so small that they weigh from 200 to 400 to the carat or 30,000 to 60,000 to the ounce.
Since 1910 a radical change has been made in the weighing of diamonds and all precious stones, the standard now being a (metric carat? of 200 milligrams, divided into hundredths in conformity with the decimal system; this change was already suggested by the present writer as far back as 1893.* This new carat, which is the one now used in all European and American countries, is equivalent in weight to 3.08647 grains. It was officially adopted in the United States, 1 July 1913.