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