Pearl Grains in Grams In Grains Troy Indian (Madras) .0518383 .799987 Austrian (Vienna) .05153+ .79526+ German (Frankfort) .05144+ .793878 Brazil and Portugal .05143+ .793801 France .051375 .792836 England .051352 .792485 Spain .051348 .792424 Holland .051261 .791077 Assuming that the gram corresponds to 15.43235 English grains, an English diamond carat will nearly equal 3.17 grains. It is, however, spoken of as being equal to four grains, the grains meant being “diamond” or “pearl” grains, and not ordinary troy or avoirdupois grains. Thus a diamond or pearl grain is but .7925 of a true grain. In an English troy ounce of 480 grains there are 151½ carats; and so it will be seen that a carat is not indeed quite 3.17 grains, but something like 3.1683168 grains, or less exactly, 3.168 grains. Further, if we accept the equivalent in grains of one gram to be, as stated above, 15.43235, and if there be 151½ carats in a troy ounce of 480 grains, it will follow that an English diamond carat is .205304 of a gram, not .205409, as commonly affirmed. The following exact equivalents, in metric grams and grains troy, of the diamond carat as used in different parts of the world in 1882, are given by Mr. Lowis d’A. Jackson: DIAMOND CARATS