a system of weights used for precious metals and gemstones, based on the grain, which is identical to the avoirdupois grain. 24 grains = 1 pennyweight; 20 pennyweights = 1 (troy) ounce; 12 ounces = 1 (troy) pound
Word origin
C14: named after Troyes, where it was first used
troy weight in American English
a system of weights for gold, silver, precious stones, etc.
Word origin
ME, after Troyes2, where first used at medieval fairs