Troy weight displaced it. Where once 240 pence made a tower pound (and 256 make a troy pound), by the time of the United Kingdom Weights and Measures Act of 1824, a troy pound gives 792 silver pence, still minted as such as Maundy Money. Sterling originally referred to the Norman silver penny of the late 11th century. The coin was minted to a fineness of 11 oz, 2 dwt (in the pound), or 925 Millesimal fineness. Troy weight Troy weight is a system of units of mass customarily used for precious metals and gemstones. One troy ounce (abbreviated "t oz" or
Fineness Fineness The fineness of a precious metal object (coin, bar, jewelry, etc.) represents the weight of "fine metal" therein, in proportion to the total weight which includes alloying base metals and any impurities. Alloy metals are added to increase hardness and durability of coins and jewelry, alter colors, decrease the cost per weight, or avoid the cost of high-purity refinement. For example, copper is added to the precious metal silver to make a more durable alloy for use in coins, housewares and jewelry. Coin silver, which was used for making silver coins in the past, contains 90% silver and 10%