TROY OUNCE AND AVOIRDUPOIS OUNCE
Precious metals such as gold and silver are often sold by the troy ounce. Many people don’t realize that an ounce of gold (and other precious metals) is weighed in a different weighing system called “troy weights”. A troy ounce is more than the typical ounce found at the grocery store. In many English speaking countries there are two systems for measuring weight. One, for precious metals, called the troy ounce.The other is for Commodities such as sugar, grains, and the typical grocery items. It is called the avoirdupois ounce.