A coin is a piece of hard material that is standardized in weight, it is produced in large quantities in order to facilitate trade, and primarily and above all has the mark of the authority that produces it.Coins are usually metal or a metallic material and sometimes made of synthetic materials, usually in the shape of a disc, and most often issued by a government. Coins are used as a form of money in transactions of various kinds, from the everyday circulation coins to the storage of large numbers of bullion coins. In the present day, coins and banknotes make up the cash forms of all modern money systems. Coins made for paying bills and (general monetized use) are usually used for lower-valued units, and banknotes for the higher values; also, in most money systems, the highest value coin made for circulation 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 making them, but this is not generally the case with historical circulation coins made of precious metals.

Coin definition

• A small piece of metal, usually flat and circular, authorized by a government for use as money.
• Metal money considered as a whole.
• A flat circular piece or object felt to resemble metal money: a pizza topped with coins of pepperoni.
• Architecture A corner or cornerstone.

Exceptions to the rule of coin face-value being higher than content value, also occur for some "bullion coins" made of silver or gold (and, rarely, other metals, such as platinum or palladium), intended for collectors or investors in precious metals. Examples of modern gold collector/investor coins include the American Gold Eagle minted by the United States, the Canadian Gold Maple Leaf minted by Canada, and the Krugerrand, minted by South Africa.Historically, a great number of coinage metals (including alloys) and other materials have been used practically, artistically, and experimentally in the production of coins for circulation, collection, and metal investment, where bullion coins often serve as more convenient stores of assured metal quantity and purity than other bullion. Check out another coin articles at your left hand side navigation.