Pound (mass) a legal unit for trade (it was abolished in the United Kingdom on 6 January 1879 by the Weights and Measures Act of 1878), but the troy ounce, of a troy pound, is still used for measurements of gems such as opals, and precious metals such as silver, platinum and particularly gold. The system called Tower weight was the more general name for King Offa's pound. This dates to 757 AD and was based on the silver penny. This in turn was struck over Arabic dirhams (2d). The pound was based on the weight of 120 Arabic silver dirhams, which
Mithqal Mithqal Mithqāl () is a unit of mass equal to 4.5 grams which is mostly used for measuring precious metals, such as gold, and other commodities, like saffron. The name was also applied as an alternative term for the gold dinar, a coin that was used throughout much of the Islamic world from the 8th century onward and survived in parts of Africa until the 19th century. The name of Mozambique's currency since 1980, the "metical", is derived from "mithqāl". The word "mithqāl" (; “weight, unit of weight”) comes from the Arabic "thaqala" (), meaning “to weigh”. Other variants of