System of measurement The same is true of quarts, gallons, etc. Six US gallons are a little less than five imperial gallons. The Avoirdupois system served as the general system of mass and weight. In addition to this there are the Troy and the Apothecaries' systems. Troy weight was customarily used for precious metals, black powder and gemstones. The troy ounce is the only unit of the system in current use; it is used for precious metals. Although the troy ounce is larger than its Avoirdupois equivalent, the pound is smaller. The obsolete troy pound was divided into 12 ounces, rather than the
Imperial Metals Corp shared by both countries are developed." Imperial Metals Corp Imperial Metals Corporation known as IMI Imperial Metals Inc until 2002, is a Canadian metals and mining company. Engaging in the acquisition, exploration, development, mining, and production of base and precious metals in North America, the majority of its holdings and operations are in British Columbia. In 2016 the Company produced 119.17 million pounds of copper, 94,930 ounces gold and 330,960 ounces silver from its Mount Polley and Red Chris mines. Imperial has two operating mines in British Columbia, one in southern Nevada, and two exploration stage projects also in British