Coin

A coin is normally a piece of hard material, generally metal, usually in the shape of a disc, and most often issued by a government, to be used as a form of money in transactions of various kinds,from the everyday circulation of the US quarter, to the storage of vast amounts of bullion coins.In modern times coins along with banknotes, coins construct the cash forms of all modern money systems. Coins made for circulation (general monetized use) are usually used for lower-valued units, and banknotes are usually used for the higher values; also, in most money systems, the highest value coin is worth less than the lowest-value note. The face value of circulation coins is usually higher than the gross value of the metal used in manufacturing them.

Exceptions to these rules take place for non-monetized "bullion coins" made of silver or gold (and, rarely, other metals, such as platinum or palladium), intended for collectors or investors in precious metals.Historically, a enormous number of coinage metals (including alloys) and other materials have been used practically, impractically (i.e., rarely), artistically, and experimentally in the construction of coins for both circulation, assortment, and metal investment