United States customary units mass: tower, apothecaries', troy, avoirdupois, and metric. Of these, the avoirdupois weight is the most common system used in the U.S., although Troy weight is still used to weigh precious metals. Apothecaries weight—once used by pharmacies—has been largely replaced by metric measurements. Tower weight fell out of use in England (due to legal prohibition in 1527) centuries ago, and was never used in the U.S. The imperial system, which is still used for some measures in the United Kingdom and other Commonwealth countries, is based on avoirdupois, with variations from U.S. customary units larger than a pound. The pound avoirdupois,
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