Circulated, Circulation. Coins changing hands in normal commerce, passing from person to person. Circulation implies that some wear takes place with every movement of the coin. A coin that has not circulated at all – uncirculated – has no wear, no tarnish, no scratches, no nicks, no damage; all these are expected to happen as coins pass through every possible environment, every bit of use, misuse and abuse that a public will do perhaps without thinking or caring for the coins in their possession. Coins are dropped on their edges, carried with keys and other objects that mar and hasten their wear – removal of a minute amount of surface metal. Considering the extremes in environments, temperature, handling, storage and use in vending, sorting, counting and rolling machines, coins hold up remarkably well. The life-span of coins are ten to twenty times that of paper money.

The wear of coins in circulation is called abrasion. The amount of circulation

and abrasion determines a coin's condition. A coin abraded beyond recognition is called a slug. A damaged coin is called impaired, or if more extensive, mutilated. A coin no longer legal to circulate is called uncurrent or obsolete.