coinage

Coinage refers to the process by which a government or monetary authority manufactures coins and issues them as legal tender. It encompasses design, metal selection, planchet preparation, minting, and distribution. Coins function as a medium of exchange, a unit of account, and a store of value within an economy.

Historically, coinage began in the second half of the 7th century BCE in Lydia (modern Turkey), spreading to Greece and the eastern Mediterranean. Over time, empires and states standardized weights and denominations, with Roman, Byzantine, Islamic, and later European authorities issuing widely circulated coins. In medieval Europe, coin production evolved from hammered to milled coinage, which helped deter clipping and counterfeiting.

Production involves creating planchets (coin blanks), often by stamping or milling, and then striking them between engraved dies. Materials range from precious metals such as gold and silver to base metals like copper, nickel, and zinc, frequently in alloys. Some coins are bimetallic, combining different metals in the center and ring. Features such as mint marks, inscriptions, and edge designs are used to identify issuing authorities and deter counterfeiting.

Coins serve as a circulating currency, a vehicle for commemorative issues, or bullion coins intended for investment. The monetary value of a coin may reflect legal tender status or its intrinsic metal content; seigniorage is the revenue earned by issuing currency. Debasement, the reduction of a coin’s metal content, has been used in various historical periods to raise funds.

In modern economies, coinage is typically produced by national mints under the authority of a central bank or treasury, with legal tender status defined by law. Although digital payments have grown, coins remain common for small transactions and savings, and coin design and security continue to adapt to evolving conditions.