| a system of weights in use for precious metals and gems (formerly also for bread, grain, etc.): 24 grains = 1 pennyweight (1.555 grams); 20 pennyweights = 1 ounce (31.103 grams); 12 ounces = 1 pound (0.373 kilogram). The grain, ounce, and pound are the same as in apothecaries' weight, the grain alone being the same as in avoirdupois weight. The troy pound is no longer a standard weight in Great Britain. |
| troy weight n. A system of units of weight in which the grain is the same as in the avoirdupois system and the pound contains 12 ounces, 240 pennyweights, or 5,760 grains. |
troy weight
traditional system of weight in the British Isles based on the grain, pennyweight (24 grains), ounce (20 pennyweights), and pound (12 ounces). The troy grain, pennyweight, and ounce have been used since the Middle Ages to weigh gold, silver, and other precious metals and stones. The name supposedly derives from the city of Troyes in France, site of one of the major medieval fairs. The troy pound was adopted by the U.S. Mint for the regulation of coinage in 1828.
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