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Coin Glossary

alloy: a mixture of two or more metals 

annealing: heating blanks in a furnace to soften the metal 

archiving: to file or collect 

assay: to analyze and determine the purity of metal 

bag mark: a mark on a coin from contact with other coins in a mint bag 

bi-metallic: a coin comprised of two different metals, bonded together 

blank: round metal disc that feeds into the upsetting mill, producing a planchet 

bullion: precious metals like gold, silver, platinum, or palladium in the form of bars or other storage shapes. Bullion coins are coins that are made of these metals and sold at bullion prices. 

business strike: a coin intended for circulation and monetary transactions (as opposed to a proof coin specially made for collectors) 

bust: a portrait on a coin, usually including the head, neck and upper shoulders 

circulating coin: a coin that's used in daily life as money 

clad coinage: coins that have a core and outer layer made of different metals. Since 1965, all United States dimes, quarters, half dollars, and dollars have been clad 

collar: a metal piece that restrains the expanding metal of a planchet during striking 

commemorative: a special coin, issued to honor an outstanding person, place, or event in history 

condition: the physical state of a coin 

counterfeit: a fake coin or other piece of currency made so that people will think it's genuine 

currency: any kind of money - coins, paper money - that's used as a medium of exchange 

date set: a collection of coins all marked with the same year 

denomination: the different values of money. United States coins come in these denominations: pennies, nickels, dimes, quarters, half dollars, and dollars 

designer: the artist who creates a coin's design (but doesn't necessarily sculpt the design) 

die: a piece of metal that has the coin's design (pictures, value, and mottoes) which is used to stamp the image onto the coin. The coining press holds both the front and back dies. 

edge: the outer border of a coin, considered the "third side" (not to be confused with "rim"). Some coins feature lettering, reeding, or ornamental designs on their edges. 

emblem: symbol or mark used as an identifying mark 

engraver: the person who sculpts a coin's design either digitally or using clay and plaster (not necessarily the designer) 

error: a coin improperly produced but not found and recycled 

face value: the sum for which a coin can be spent or exchanged (a dime's face value is 10¢) as opposed to its collector or precious metal value 

field: the portion of a coin's surface not used for design or inscription 

hairlines: tiny lines or scratches on coins, usually caused by cleaning or polishing 

incuse: opposite of relief, the part of a coin's design that is pressed into the surface 

inscription: the legend or lettering on a coin 

key date: a scarce date required to complete a collection, usually more difficult to find 

legal tender: coins, dollar bills, or other currency issued by a government as official money 

legend: principal lettering on a coin 

medal: a metal object resembling a coin but not used for legal tender 

medallion: a large medal 

mint: a place where coins are made. The United States Mint facilities in Philadelphia and Denver produce all circulating coins for this country. 

mint luster: the dull, frosty, or satiny shine found on uncirculated coins 

mint mark: a small letter on a coin identifying which mint struck the coin 

mint police: this special force protects all Mint buildings, including the four production facilities, the headquarters building, and Fort Knox Bullion Depository 

mint set: a complete set of coins of each denomination produced by a particular mint 

mint state: same as uncirculated 

mintage: the quantity of coins produced 

motto: a phrase or slogan on a coin that is symbolic of a country's ideals 

numismatics: the study and collecting of things that are used as money, including coins, tokens, paper bills, and medals 

obsolete: a coin design or type that is no longer produced 

obverse: the front (or "heads") side of a coin. It usually has the date, mint mark, and main design. 

pattern: an experimental or trial piece, generally of a new design or metal 

pickle: to soak in a liquid for some time 

planchet: the blank piece of metal on which a coin design is stamped 

precious metals: gold, silver, and other rare metals that are valuable 

proof: a specially produced coin made from highly polished planchets and dies and often struck twice to accent the design 

proof set: a complete set of proof coins of each denomination made in a year 

reeding: raised lines across the edge of a coin 

relief: opposite of incuse, the part of a coin's design that is raised above the surface 

restrike: a coin that is minted using the original dies but at a later date 

reverse: the back (or "tails") side of a coin 

riddler: a machine that screens out blanks (planchets) that are the wrong size or shape 

rim: the raised edge on both sides of a coin (created by the upsetting mill) that helps protect the coin's design from wear 

roll: coins packaged by banks or dealers. The number of coins in a roll depends on the denomination: 50 cents, 40 nickels, 50 dimes, 40 quarters, 20 half dollars, or 20 dollar. 

seal: an official symbol or mark 

series: a collection of coins that contains all date and mint marks of a specific design and denomination. For example, a Kennedy series would include a Kennedy half dollar from each year since the coins were first issued. 

strike: the process of stamping a coin planchet with a design. The strength of the imprint - full, average, or weak - affects the value of rare coins. 

type set: a collection of coins based on denomination. For example, a nickel type set would contain one of each of the four types of nickels that the United States Mint has produced. 

uncirculated: a coin in new condition that doesn't have any signs of wear 

upsetting mill: a machine that raises the rim on both sides of a blank, producing a planchet 

variety: a minor change from the basic design type of a coin 

year set: a collection of all coins issued by a country for any one year