The
troy ounce (
oz t) is a unit of
imperial measure, now commonly used to measure the mass (weight, in common parlance) of
precious metals. One troy ounce is defined as exactly 31.1034768
g, which may be used to denote the value of a precious metal. One troy ounce of
gold is denoted with the
ISO 4217 currency code XAU, while one troy ounce of
silver is denoted as XAG.