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 on the continent. The troy ounce and grain were also part of the apothecaries' system. This was long used in medicine, but has now been largely replaced by the metric system (milligrams). The only troy weight in widespread use today is the British Imperial troy ounce and its American counterpart. Both are currently based on a grain of 0.06479891 gram (exact, by definition), with 480 grains to a troy ounce (compared with grains for an ounce avoirdupois). The British Empire abolished the 12-ounce troy pound in the 19th century, though it has been retained (although rarely used) in the American