Adjustment Marks On early US gold, the planchets were at times slightly overweight. The raw plnachets were filed down to the proper weight. Those file marks came through the minting process and are known as Adjustment Marks.
Altered Any coin which has been physically altered an an attempt to enhance the look of the coin. Artificial Toning, Whizzing, changing mintmarks/dates are examples of altered coins.
Annealing The process of heating blank planchets prior to minting so as to soften the metal.
Assay Raw gold and non mint gold product is of unknown gold content. The process of determining the amount of pure gold in whatever from of raw or minted gold is called Assaying. In the old west an Assay office determined the actual gold content of nuggets miners found.
Artificial Toning The process of artificially, ehancing a coins color or look through chemical or extreme heat/cold means. Typically a bluish or dark brown color. Many times toned coins are spotty. Natural Toning normally blends into the coin's surfaces and doesnt stand out.
Bagmark Newly minted coins are gathered in bins then put into cloth bags. Through this process the coins hit each other putting Bagmarks or hits on the coin.
Basining The process of polishing the face of a die.
Blank Planchet The round disk (Type I Blank) cut from strips of rolled metal which are fed trough a milling machine which puts a slight rim on the coin (Type II Blank). The Blanks (Type II) are fed through the minting process where the final product is produced.
Body Bag When Third Party Grading Services believe a coin has a significant problem that they will not encapsulate the coin, the coin is returned in a plastic polyvinyl bag inside a flip. That bag is affectionately known as a Body Bag.
Brockage A coin that has been struck in a die that still has an existing coin in it. The brockage coin will have an inverted impression of the original coin on one side.
Bullion The term for coins or medals minted out of precious metals (Gold, Silver, Palladium or Platinum) that carry little to no numismatic premium.
Burnishing The process of polishing the blank planchets, usually reserved for proof coinage.
Cameo A coin that has a noticeable degree of contrast between the portrait/devices and the field. Cameos can be on proof or uncirculated coins. Normally the fields of such coins posses deep mirrors which accentuate the contrast.
Carbon Spots These are small black spots of carbon that appear on a coin. They can not be removed and can grow over time.
Cartwheel Effect The effect a highly lusterous coin has when rotated in a circular motion
Cast Counterfeit A counterfeit coin that is made in a cast vs a counterfeit that was struck from dies.
Cherrypick Finding a rare variety or rare attribute among a group of similar coins. A roll of Morgan Dollars was Cherrypicked for the finest coin.
Circulated A coin that has wear. Circulated coins range in grade from Poor to Almost Uncirculated.
Clad - Composition metal coin with a sandwich layer which is the clad layer, with two outer layers for the obverse and reverse.
Clashmarks Clashmarks appear on a coin from clashed dies. They are the inverse impression of the opposite side of a coin due to the dies having clashed.
Clashed Die When the two die strike each other without a blank planchet. The impression of each side of the coin is somehwhat imparted on the opposite side of the coin.
Cleaning The act of attempting, through some sort of solvent or rubbing to take contaminants off a coin. Cleaning more often than not results in damage to the coin. Any cleaning that is necessary due to contaminants that might continue to harm the coin should be left to the experts. PVC is an example of a contaminant that should be removed from a coin.
Clipped Planchet A planchet that was cut out of the edge of a strip that is missing a portion of the intended circumference (A straight clip), or a planchet that was cut two or more times rendering a round clip.
Collar The portion of the press that keeps the sides of the blank planchet from expanding beyond the desired size. The collar also imparts the edge to the coin (reeded or lettered)
Counterfeit Any coin that is not made by the authorized minting authority.
Counterstamped A stamp signifying a special event that is struck into the coin after the coin has been produced. These are always post mint counterstamps. Some have significant historical significance and can positively affect the value. Example Stone Mountain counterstamps.
Crown Any large dollar size coin the circulated in European countries.
Cud When a die has a piece that has broken off, the result is a raised portion on the coin in the area of the broken die. That raised area is known as a Cud.
Devices The normally raised portion of a coin that are not a part of the central design of the obverse or reverse. The lettering and date are part of the devices of a coin.
Die/Die Pair The actual inverse impression of the actual coin on hardened steel cylinder. This is what stamps the blank planchets in the minting process. A Die Pair is the pair of dies which strike the obverse and reverse of a particular coin.
Die Punch A punch used to add a date or mintmark to a hub or working hub.
Dipping The act of putting a coin in a mild acid bath to remove contaminants. Done correctly will not hurt the coin. Done excessively, the coin will loose luster and become lacklusteror over dipped.
Double Die A coin struck by a working die that has two slightly rotated impressions from a working hub. This is not to be confused with machine doubling which creates a shelf like doubling affect on the coin. True double dies are rare and several are very popular varieties within a series of coins.
Eye Appeal The overall appeal of a coin. Eye appeal is what first strikes you about a coin. Eye appeal is one of the primary determinants of grade. Eye appeal can be good or bad.
Fasces A Roman symbolic ax depicted on some US coins. Example the reverse of the Winged Liberty Dime.
Field The flat part of a coin. In the die the field is the highest portion of the die. The portrait and devices are sunken into the die, just the opposite of the finished product.
Galvano A large plaster relief of a coins design/ this is used to transfer the design to a working die. See Reduction.
Grading Scale The commonly used Sheldon scale from 1-70. Also in adjectival form.
Hairlines Minute lines, typically on proof coins which were caused by light cleaning, polishing or light contact with plastic flips or plastic slides.
Hub/Working Hub A working die is stamped into a metal hub. This hub is then used to create the working dies.
Impaired Proof A proof coin that has actual wear on the coin or other problems that would keep the coin from grading at least Proof 60. Impaired proofs take on the grading scale just like Circulated coins, however they get a PR designation in front of the numeric grade.
Incuse When the design of the coin is cut into the coin, it is said to be incuse. On incuse coins, the fields are the high points. Indian $2 ½ and $5 are examples of incuse designs on US coins.
Ingot A bar of metal, usually precious metal formed in a brick like shape. These can range from small 1-2 ounces to very large, 900 ounces +.
Iridescent Toning Toning which appears to float above the surface of the coin. The luster of the coin MUST be very evident underneath thee toning. Only full mint luster coins can have Iridescent Toning.
Luster The sheen imparted by a coin. Original luster is the sheen imparted during the minting process. A washedout or over dipped coin is said to be lacking luster. Gem coin must have full mint luster.
Master Die A die that is used to produce a working hub. A master die can be used for years.
Milk Spots White spots that appear on proof coins. These spots are part of the coin and can not be removed by any known process.
Mint State Also known as uncirculated. Mint State coins rnage in grade from MS60 (Basal) to MS70 (perfect). All Mint State coins have no wear what so ever.
Mint Sets A complete set of circulation strike coins from each mint and each denomination. These were sold by the mint beginning in 1948. From 1948-1958, mint sets were housed in cardboard holders, of which 2 of each coin from each mint were included. Some of these sets have spectacular toning to them. Beginning in 1959, only one coin from each year was included and the packaging was changed to a plastic package in a paper envelope.
Mule A double denomination coin that has an obverse of one denomination and reverse of another. These are extremely rare, however, do exist.
Multiple Strike A coin that has been struck more than one time in a rotated fashion. This is not to be confused with a double die.
Obverse The front side of a coin. Typically that is the side with the date and the portrait.
Off-Center A coin that has been struck un centered in the press. Both sides of the coin will have the same blank area.
Original Die A die made for use during the year of issue (date) vs a restrike die used for making the same date coin years later.
Original Set Original sets are sets of coins, typically from one year that were issued together and not replaced by other coins.
Overdate A coin that has a numeral or two from a different year in it. This typically occurred as the mint was attempting to use a previous years working hub. Example 1943/2 Jefferson Nickel.
Over Mintmark Similar to an Overdate, however, the mintmark is stamped twice into the coin (d/d) or another mints hub was passed along creating an over mintmark with two mint marks. Example 1900 O/CC.
Pattern A coin that proposed either by someone at the mint or other that is actually produced as a coin, but never adopted for general use.
Pedigree Some famous and rare coins have ownership traced to major collections or auctions. A coin that can be traced over time, tends to have more value, due to its Pedigree.
Planchet See Blank Planchet
Planchet Defect - A defect on the planchet that was not eliminated during the striking process. A piece of metal of dirt in the die can cause this, as well as a problem with the original planchet that was fed into the die.
Plug A hole filled on a coin is done with a plug. The plug is inserted in the hole and then ground down to be smooth with the fields. A plugged coin can still have value if the overall coin is rare enough. They will bring considerably less than an original unplugged coin. Typically plugged coins are from the 18th and 19th century.
Portrait Typically on the obverse of the coin, the portrait can be a person, or an image (in the US, the image of Liberty is ubiquitous)
Press The machine used to produce the actual coin. Can be a machine press, screw press or hammer press.
Proof A coin made from specially prepared dies and blank planchets. Proof coins are struck at least twice to fully bring out the design. Proofs are meant to be as near as possible to the top of the coiners art.
Proof Set A set of proof coins usually cent through half/dollar that has been packaged as a group by the mint. Proof sets have been produced since 1950. Prior to that coins were sold as individual pieces. Collectors could buy one of each and assemble their own proof set.
Prooflike/Deep Mirror Prooflike The term used to describe business strike coins that have reflective fields. They look similar to proofs, however, do not exhibit the unusually strong strike of prods, nor the squared rims. Usually reserved for Morgan Silver Dollars. Deep Mirror Prooflikes have mirrors that reflect clearly at least 4. Prooflikes must reflect at least 2.
Prototype Pattern coins which virtually are identical to the coins adopted for general use. Usually dated the year prior to the general use coin. Example 1863 Two Cent Piece
PVC Poly Vinyl Chloride. This chemical is present in soft plastic flips. Its the chemical that keeps the plastic soft. It also will put a greenish film on coins. If left too long in PVC flips, a coin can be damaged permanently. Any PVC on a coin should be removed professionally and immediately. Never store coin in PVC flips, even for a second.
Rainbow Toned Coin A coin that has a very vibrant colored patina. To be rainbow toned, several colors of the rainbow should be present. Normally, deep greens, blues, oranges and reds dictate a Rainbow Toned coin.
Rarity Scale/Sheldon Scale The scale by which rarity in terms of known or likely known specimens of a particular coin exist.
Reduction The transfer of a coins design from a Galvano to a Master Die which is actual size. See Galvano.
Reeding The edge treatment of most US coins of dime denomination or larger. The Reeding is imparted by the collar during the striking process.
Reverse The back of a coin. Normally the reverse will have some sort of eagle or shield.
Relief The depth of the devices and portrait on a coin. Some coins come if high relief and low relief varieties. The most famous of these is the 1907 High Relief Saint Gaudens Twenty Dollar Gold.
Restrike A coin that is struck after the year it was intended to be struck. Restrike occurred mostly in the mid 1850s when collector demand began to rise. Prominent collectors asked the mint to recreate certain coins they could not find. These coins are restrikes and have different characteristics than the originals.
Rim The outer most part of the coin, normally raised.
Rockford Test The mint tested the strength of the metal in the blank planchets and finished coins with a special metal strength test called a Rockford Test. A steel pin was pressed into the blank or finished coin at a standard pressure. The resistance of the coin to the punch determined the strength of the metal. Rockford Test Punch coins exist, however, are extremely rare. The test punch is normally on the obverse and looks as though the coin were shoot with a single BB.
Seignorage The difference between the actual cost of producing a coin and the face value of that coin. It is the profit, so to speak, of the mint.
Slider A coin that appears to be uncirculated, however, upon closer inspection, has the slightest bit of wear.
Special Mint Sets The were sets that were minted from 1965-1967. This was a transitional time at the mint, as the mint was moving away from 90% silver coins. The Special Mint Set (SMS) coins were specially prepared, however, much less care was given to them than proof coins. They were only struck once, compared to proofs which were struck twice from specially prepared dies and planchets. These sets were issued in 5 coin sets from cent to half dollar. A few 1964 SMS coins were minted in 1964, and are extremely rare. Authentication is mandatory.
Striation Die polish lines that run close to parallel in the fields of a coin. They are caused by polishing of the dies and or harsh blank planchets.
Strike How well the relief of a coin is minted in a particular coin. Strikes range from weak to strong. Many dates of a particular denomination are notorious for weak strikes. Some dates normally come with full strikes. It is important to understand how a particular date and mint strike normally comes.
Strip A rolled piece of metal that the blank planchets are cut from.
Thaler A large German coin about the size of a silver dollar. This is the forerunner of the US term Dollar.
Toned Coin A coin that has some not mint imparted patina. The patina can be any color. Some toned coins are very impressive, others are downright ugly. Toning can add to or detract from the overall value of the coin.
Trial Strike A coin that has been struck in an attempt to adjust the pressure of the dies. A trial strike normally is a very very weakly struck coin.
Uncirculated A coin that has absolutely no wear. Uncirculated coins are also called Mint State coins. Grades range from Mint State (MS) 60 through MS70.
Upset Mill The machine that imparts the first portion of the edge on a blank panchet.
Variety A variation of a particular coin. Some dates have several die varieties. Example 1954 D/S nickels, or any VAM variety.
Wear Once an uncirculated coin is touched, a small portion of the luster is removed. This is called wear.
Whizzing The process of attempting to add luster to a coin by polishing the coin with a buffing wheel.
Working Hub Also called a hub. The working hub is made from a master die and is used to make working dies.
Working Die A die that is made from a working hub. Working dies are the dies which produce the actual coins.