Carat (mass) g or possibly up to 5 g less. Therefore, the metric equivalent of 1 "siliqua" was approximately 189 mg. The Greeks had a similar unit of the same value. Gold fineness in carats comes from carats and grains of gold in a solidus of coin. The conversion rates 1 solidus = 24 carats, 1 carat = 4 grains still stand. Woolhouse's "Measures, Weights and Moneys of all Nations" gives gold fineness in carats of 4 grains, and silver in pounds of 12 troy ounces of 20 pennyweight each. Carat (mass) The carat (ct) (not to be confused with the karat,
Troy weight 7716 BI grains, but after the union, rounded to 7680 BI grains. This divides to 16 ounces, each of 16 drops, each of 30 grains. The rounding makes the ounce and grain equal to the English standard. The Dutch troy system is based on a Mark, of 8 Ounces, the ounce of 20 Engels (pennyweight), the Engel of 32 As. The mark was rated as 3798 Grains, English troy, or 246.084 metric grams. The divisions are identical to the tower system. The troy system was used in the apothecaries' system, but with different further subdivisions. King Offa's currency reform replaced