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A system of weights based on a pound of 16 ounces. It is the primary system used in the United States. See also Troy weight.
A unit of mass customarily used for precious metals and gemstones. One troy ounce is equal to 480 grains (or 31.1034768 grams, or 1.0971 avoirdupois ounces). There are 12 troy ounces in a troy pound that contains 5760 grains (an avoirdupois pound contains 7000 grains).