pieces of metal bearing distinctive marking to authorize their use as money (circulation and payment). Formerly made of gold, silver, copper, and copper alloys, coins at present are primarily made from alloys of copper, nickel, and aluminum. Oval or round coins have almost always predominated as the most convenient means of circulation. Coins are described in terms of their obverse (face), reverse (back), and edge. Every coin has a depiction (coat of arms, name, title, or representation of a ruler) and a legend, consisting of the name of a city or state, the year of minting, and the coin’s denomination.

Coins appeared almost simultaneously in the Asia Minor state of Lydia (in the late eighth or the early seventh century B.C.) and in ancient Greece, on the island of Aegina (seventh century B.C.). In medieval Europe and Rus’ the local minting of coins began in the ninth or tenth centuries. The availability of national coins gradually caused Roman, Byzantine, and Arab coins, as well as their imitations, to go out of circulation. With the formation of a unified, national Russian state at the beginning of the 16th century, a standard system of coinage came into being. In accordance with the Reform of 1534, state coins—kopeks—were minted.

The use of coins is related to the development of commodity-money relations and trade. Because the quality and weight of the metal used in coins were guaranteed by the state (state mints), coins replaced bartered goods (livestock, grain, shells) and metal ingots as the universal means of payment. The issue of coins is the exclusive right of a sovereign power. In feudal Europe the right to mint coins was held by any sovereign feudal lord (extending to members of the untitled gentry); more recently it has been under the jurisdiction of national governments. The issue of coins by private individuals has always been regarded as a very serious criminal and political offense. Images on coins (during the early period found only on the obverse) are state emblems. Coins are obligatory means of payment within the state that issues them. Some coins were circulated far from the places where they were minted (for example, Roman silver coins were used beyond the borders of the empire; Arab dirhams were circulated in Eastern Europe from the ninth to 13th centuries).

The fundamental principles of coinage are determined by the monetary system adopted by the state. The weight of coins at the time of minting (“tolerance” is the term used to designate a legal departure from the adopted weight), the selection of a metal that is to be the basis of a given system, and the relative value of coin metals in relation to one another are determined by law. In slaveholding societies, particularly during the Middle Ages, the debasement of coins often occurred (a reduction in weight or purity by the state authority while retaining their former face value). As a result of debasement, the rulers minting the coins profited.

With the appearance of paper money, coins no longer served as the principal means of payment. However, coins made of valuable metals are regarded as treasures. During the 20th century coins are used universally as small change, with a standard rate of exchange in relation to paper money. Gold and silver coins are rarely issued and do not have any serious economic significance; in most cases they are commemorative (or anniversary) coins.

The first Soviet coins were minted in 1921; the coins now in circulation have been minted since 1961. In 1965 the USSR issued a commemorative ruble, dedicated to the 20th anniversary of victory in the Great Patriotic War of 1941–45. Anniversary coins were minted in 1967 in denominations of 10 kopeks, 15 kopeks, 20 kopeks, 50 kopeks, and 1 ruble to mark the 50th Anniversary of the Great October Socialist Revolution. In 1970 a commemorative ruble was issued to mark the 100th Anniversary of V. I. Lenin’s birth.

The science of coins is called numismatics.