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,
Pennyweight Act of 1878; only the Troy ounce and its decimal subdivisions remained official. The Troy ounce enjoys a specific legal exemption from metrication in the UK. The pennyweight is the common weight used in the valuation and measurement of precious metals. Jewellers use the pennyweight in calculating the amount and cost of precious metals used in fabricating or casting jewellery. Similarly, dentists and dental labs still use the pennyweight as the measure of precious metals in dental crowns and inlays. Pennyweight and grains are still used to weigh gooseberries in competitions in Cheshire, northwest UK. Over the Pennines in Yorkshire