Marks made on a coinage blank to ensure consistency when used to become a coin.
The act of adding or changing a date or mint mark outside of a mint, usually to create the appearance a coin is a rarity.
Heating of coin blanks to soften them prior to being struck with coinage dies.
Tarnish appearing on a coin caused by purposeful improper storage to create the surface colors now appearing on that coin.
A destructive test through which the purity of metal can be determined.
Detrimental marks on the surface of a coin caused by banging against other coins when stored in bags.
A promissory note issued by a banking agency through which assets are pledged valued at the same amount as the note issued against those assets.
A border of dots around the edge of a coin.
An alloy of copper and silver also known as potin, but containing more than half copper.
A pie-shaped piece cut from a Spanish 8-real coin to make change.
The round metal disk, or planchet, specially cut in preparation for the coin images to be added to make a coin.
The area of a coin show where dealers buy and sell coins.
A remote mint facility that aids coinage production centralized at the main mint.
An error coin on which one side is struck correctly, however the other side is the incuse mirror image of this other side.
Platinum, palladium, gold or silver coins struck to a specific weight and purity and meant to be traded for their intrinsic value rather than for their legal tender face value. THese coins do not command a premium above this precious metal value. They are a convenience, circumventing the need for assaying the metal when it is sold.
A minting process through which coinage surfaces are brightened.
A coin made by mass production and intended to circulate as money. The majority of coins encountered in coin collections will be business strikes.
The rub a coin receives from movement while in storage in a coin collection.
Detrimental oxidation specks appearing on the surfaces of a coin.
THe surface brilliance of an uncirculated coin originating from when the coin was first produced. This brilliance disappears when a coin circulates or is cleaned.
Name adopted by the Coinage Act of 1792 for a gold
coin valued at 10 units or $10. Also a name used to refer to gold, silver, and
platinum coins of the American Eagle bullion coinage program begun in 1986.
The cylindrical surface of a coin between the two
sides. The edge can be plain, reeded, ornamented, or lettered.
A copy of a coin, medal, or token made by
The person who designs the coinage dies; known as a celator in ancient times.
Coins displaying problems due to mistakes made during production.
Also called an essai, the term represents experimental pieces, pattern coins, transitional and trial pieces.
The lower segment of a coin, below the main design,
generally separated by a line and often containing the date, designer initials,
The perception of a coin or bank note from the item's outward appearance. This can include toning, strike quality, centering and other such factors, other than condition.
The nominal legal-tender value assigned to a
given coin by the governing authority.
A coin that was never officially struck, such as an 1868 U.S. large cent or a coin issued by the non-existent nation of Sealand.
A Roman symbol of authority consisting of a bound
bundle of rods and an axe.
The flat area of a coin's obverse or reverse, devoid
of devices or inscriptions.
The purity of a precious metal of a coins, typically expressed in decimal form such as .916 fine rather than as 22 karat. A .916 fine coin has 91.6 percent of that metal in it.
A 2-by-2 inch clear plastic holder into which a collectible coin is often placed.
Lines that are not always visible that are caused by the metal flow from the center of the coinage blank caused at the moment the blank was struck by the working coinage dies.
A counterfeit, an unauthorized coin or bank note meant to deceive.
Wear appearing only on the highest points of coinage detail on a high grade coin.
A reproduction of a proposed design from an
artist's original model produced in plaster or other substance and then
electroplated with metal. The galvano is then used in a reducing lathe to make a
die or hub.
A heraldic term for stars, rays or other devices
placed as if in the sky or luminous.
The largely subjective practice of providing a
numerical or adjectival ranking of the condition of a coin, token, or medal. The
grade is often a major determinant of value.
The name for the observation made by Sir
Thomas Gresham, 16th century English financier, that when two coins with the
same face value but different intrinsic values are in circulation at the same
time, the one with the lesser intrinsic value will remain in circulation while
the other is hoarded.
Name adopted by the Coinage Act of 1792 for a
gold coin valued at five units or $5.
A piece of die steel showing the coinage devices in
relief. The hub is used to produce a die that, in contrast, has the relief
details incuse. The die is then used to produce the final coin, which looks much
the same as the hub. Hubs may be reused to make new dies.
A coin' principal lettering, generally shown along
its outer perimeter.
Incuse or raised lettering on a coin's
A proof coin on which the surface is granular
or dull. On U.S. coins this type of surface was used on proofs of the early 20th
century. The process has since been abandoned.
A term sometimes used to describe a coin
with two heads or two tails. Such a coin is considered impossible in normal
production due to physical differences in obverse and reverse die mountings,
though as of 2001 two have been certified as genuine by professional coin
authenticators. The vast majority are products made outside the Mint as novelty
Made to commemorate an event or person. Medals differ
from coins in that a medal is not legal tender and, in general, is not produced
with the intent of circulating as money.
Medals are generally struck with the
coinage dies facing the same direction during striking. When held by the top and
bottom edge and rotated from side-to-side, a piece struck in this manner will
show both the obverse and reverse right side up.
The total number of coins struck during a given
time frame, generally one year.
A letter or other marking on a coin's surface to
identify the mint at which the coin was struck.
The combination of two coinage dies not intended for
The science, study or collecting of coins,
tokens, medals, paper money, and related items.
The front or "heads" side of a coin, medal, or
Variety produced when one or more digits of the
date are re-engraved over an old date on a die at the Mint, generally to save on
dies or correct an error. Portions of the old date can still be seen under the
Variety created at the Mint when a different
mintmark is punched over an already existing mint-mark, generally done to make a
coinage die already punched for one mint usable at another. Portions of the old
mintmark can still be seen under the new one.
A coin, token or medal struck over another coin,
token, or medal.
A trial strike of a proposed coin design, issued by
the Mint or authorized agent of a governing authority. Patterns can be in a
variety of metals, thicknesses, and sizes.
A close-fitting, egg-shell-shaped hat placed
on the head of a freed slave when Rome was in its ascendancy. Hung from a pole,
it was a popular symbol of freedom during the French Revolution and in 18th
century United States.
A disc of metal or other material on which the
image of the dies are impressed, resulting in a finished coin. Also sometimes
called a blank.
A coin struck twice or more from specially polished
dies and polished planchets. Modern proofs are prepared with a mirror finish.
Early 20th century proofs were prepared with a matte surface.
A prooflike coin exhibits some of the
characteristics of a proof despite having been struck by regular production
processes. Many Morgan dollars are found with prooflike surfaces. The field will
have a mirror background similar to that of a proof, and design details are
frosted like some proofs.
Name adopted by the Coinage Act of 1792 for a
gold coin valued at 2.5 units or $2.50.
Serrated (toothlike) ornamentation applied to the coin's edge during striking.
The portion of a design raised above the surface of
a coin, medal, or token.
A coin, medal or token produced from original dies
at a later date, often with the purpose of sale to collectors.
The backside or "tails" side of a coin, medal or
token, opposite from the principal figure of the design or obverse.
The raised area bordering the edge and surrounding the
The complete group of coins of the same denomination
and design and representing all issuing mints.
A privately issued piece, generally in metal, with a
represented value in trade or offer of service. Tokens are also produced for
A coin from a given series representing the basic
design. A type coin is collected as an example of a particular design rather
than for its date and mint-mark.
Any coin noticeably different in dies from another
of the same design, date and mint. Overdate and overmint marks are examples of
Created when coinage metal flows between the
coinage die and collar, producing a thin flange of coin metal at the outside
edge or edges of a coin.