Click the letter below to go to terms under that heading
A
ACID COIN: A coin, typically a copper cent, dipped in nitrous acid so that it loses weight and might look like an error, such as cent on a dime planchet.
ALLOY: Two or more metals, often cited as cupro-nickel (copper and nickel), or brass (copper and zinc) or bronze, (copper and tin). (See BRASS, BRONZE.)
ALTERED DATE: A doctored date on a coin to falsely increase its value.
ANNEALING: Heating and warming metal or planchets so that they do not crack when struck at the mint. (See IMPROPER ANNEALING.)
ARTIFICIAL TONING: Changing the color of a coin’s metal via heat, sulfur or other chemical process to resemble natural toning, or patina, and increasing the value of a coin. (See PATINA.)
ASSAY: Testing the purity of a precious metal.
AUTHENTICATION: A process by which numismatists evaluate a coin according to grade, variety, error, condition and genuineness.
B
BAG MARKS: Coins stored in mint bags that strike each other and leave marks, decreasing value. (See CLEANING MARKS, WHIZZING.)
BAR NICKEL: Excess metal between the rim and the edge on a date or device typically found on 1960-D Jefferson nickels.
BASAL STATE: A coin so worn that only a part of the legend or devices are visible.
BASE METAL: Usually copper-nickel alloys used in counterfeit coins. Also, gold and silver are not magnetic. If a coin sticks to a magnet, it is fake. Here’s an example of a base metal fake Morgan dollar:
BEADING: A raised and dotted border on a coin.
BEZEL: A metal ring holding a coin so that it can be worn as jewelry.
“B-G“: Initials from last names of Walter Breen (“B”) and Ronald J. Gillio (“G”) who catalogued California Fractional Gold. Authentic examples are holdered with their initials, as in the coin below.
BIE: A die chip between the letters “B” and “E” of a Lincoln cent.
BILLON: A coin diluting silver with an alloy so that precious metal content is less than 50%, as in the 35% silver content of the Jefferson War Nickel.
BI-METALLIC: A coin comprised of two or more metals.
“BLACK BEAUTY” NICKEL: A 1958-59 nickel minted with an improper alloy mix due to trace amounts of cobalt or silicon in the refining process. Note: ANACS uses the term “Black Beauty”; all other black-toned Jefferson nickels are improperly annealed coins. (See ANNEALING.)
BLAKESLEY EFFECT: Coins struck from clipped planchets where the rim opposite the clip appears weak, wide, or even absent. (See PLANCHET.)
BLANK: Another word for planchet. Below is a coin blank you can buy online, not from the mint. (See PLANCHET.)
BLEB: A raised, rounded bump often a result of die erosion usually appearing as a flat elevation in the field. (See OCCLUDED GAS BUBBLE.)
BOURSE: The room or area where dealers display their coins, as in a coin show.
BRASS: Copper-zinc alloy.
BRILLIANT UNCIRCULATED: A well-struck coin that has not seen circulation and that posses luster or eye appeal.
BROAD STRUCK: A minting error resulting in a coin outside its collar.
BROCKAGE: one side of the coin has the normal design and the other has a mirror image of the same design impressed on it.
BROKEN POST/FILLED MINTMARK: Coin struck by a damaged die whose post broke off, leaving a filled-in appearance where the mintmark should be. No collector value.
BRONZE: Copper-tin alloy.
BULLION: Precious metals cast as bars and coins. Here are examples from the U.S. Mint:
BURNISHED: A special treatment or minting process to give a coin a sandy look or matte surface.
BUSINESS STRIKE: Coins minted for circulation (see left cent below), as opposed to Proof (see right cent), minted for collectors. Devices in business strikes often exhibit wear or poor strikes. Devices in proof coins are as designer intended. (See PROOF.)
BUST: Typically the head, upper body and shoulders of a portrait. (See TRUNCATION.)
C
CAMEO/DEEP CAMEO: A glossy or matte surface on devices, appearing frosty on both sides of the coin, distinguishing them from the fields. Degree of frostiness establishes designation. If one side is deep cameo and another side, only cameo (depicted below), designation is cameo.
CAPPED DIE: A coin that got stuck in the die with multiple strikes forming a cap on the lower or upper die.
CARAT: The weight of precious stones. (See KARAT.)
CARBON SPOT: A contaminant often from a person’s fingers reacting with copper to form black spots.
CAST: Coins made by pouring a metal into a mold as opposed to ancient coins that were struck.
CASTING BUBBLES: Tiny pockets of air that form when metal is poured into a mold, indicating the coin is probably counterfeit.
CENT DESIGNATIONS (R, RB, B): Colors describing the brilliance or patina on cents, not only Lincoln cents but the denomination. Values for “red” brilliant uncirculated cents command the highest retail prices.
CERTIFICATION: A holdered coin, gem, or medal signifying a grade or condition. Top companies include PCGS, NGC, ANACS, ICG, CAC. You can check the authenticity of a coin by its company’s database, as in PCGS Certification. (See HOLDERED, SLAB.)
CIRCULATED: A coin that shows wear from handling in commerce. (See UNCIRCULATED.)
CHAIN STRIKE: A coin created when two coin blanks are positioned too close together during the striking process, causing their edges to flatten and fuse, forming a straight or curved line resembling a chain link.
CHOP MARK: A symbol stamped on a coin other than by the U.S. Mint to prove authenticity.
CLAD: The center of a coin with one metal and a different metal for the outer layer.
CLASH MARKS: A coin struck after an upper and lower die strikes in the absence of planchet so that subsequent coins have reverse images on obverse and vice versa.
CLEANING MARKS: Removing surface luster by wiping, whizzing, dipping leaving marks with telltale circular or zigzag lines. (See BAG MARKS, DIPPING.)
CLIPPED PLANCHET: A defective coin blank or a regular one that was misfed during the striking process.
COIN ALIGNMENT: How a coin has been struck on obverse and reverse, including the rim or collar. Also, the orientation of coins as opposed to medals.
COLLAR: Outer ring of the die, slightly raised. (See MISALIGNED COLLAR.)
COLLAR CLASH: Occurs when a die shifts during striking and comes into contact with the collar, transferring features to the die and coins struck by that die and often appearing as a double rim.
COMMEMORATIVE: A coin honoring a person, event or occasion.
CONDITION RARITY: A coin rare in mint state, often because it was never collected in that condition, as in the 1884-S Morgan Dollar, with a mintage of 3.2 million, worth $300 in AU50 and $900,000 in MS68. (See RARITY.)
CONTACT MARK: Abrasions on a coin. (See BAG MARK.)
COUNTERFEIT: A fake coin or currency.
COUNTERSTAMP (or mark): Minting a picture or symbol and over-stamping it on the field of a coin. JFK and Lincoln were assassinated presidents. The Lincoln stamp on a Kennedy half is common.
CUD: A flaw that raises metal near the collar or edge, caused by a damaged die at the mint.
CULL: A coin so worn or defective that it essentially is only worth its metal content. (See FACE VALUE.)
D
DEEP MIRROR PROOFLIKE (DMPL)/PROOFLIKE (PL): Mirror-like reflectivity of 4-6 inches for DMPL and 2-4 inches for PL used in coins of all denominations, not just Morgan dollars.
DEFECTIVE PLANCHET: A blank containing several mint errors associated with the planchet rather than the die. (See PLANCHET.)
DENTICLES: Beaded or tooth-like design just after the rim of a coin.
DESIGNER: The artist or sculptor who creates a prototype for a coin. Note: Pictured below is Augustus Saint-Gaudens, considered the top designer in U.S. Mint history.
DESIGNER INITIALS: Initials of the artist who designed the coin, often misconstrued as mint marks.
DEVICE: A symbol, image, motto or emblem in the coin’s design, as distinguished from the fields.
DIE: The engraved metal creating devices used in the striking of a coin.
DIE CAP: A valuable error when a coin sticks to the hammer with metal flow around the rest of the coin.
DIE CHATTER: A coin whose lettering or devices appear to be doubled die but are a result of a die bouncing during the striking process.
DIE CHIP: A small piece of metal not part of the original design comes into contact with the metal dies.
DIE CLASH: A coin whose obverse and reverse dies strike each other without a blank coin in between, causing ghost-like images to appear on subsequent coins.
DIE CRACK: A raised line of metal due to a crack filled in by metal. (See SPLIT DIE.)
DIE DETERIORATION: Coins stuck on worn die so that dates and devices may seem doubled and irregular, with the surface often appearing blurred, bloated and/or enlarged.
DIE GOUGE: An error caused by a foreign object physically digging into the face of a minting die, allowing metal to flow into the divot thereby creating a raised area on the finished coin.
DIE MARRIAGE: a specific pairing of an obverse die and a reverse die used to strike coins.
DIE POLISH LINES: Master dies get worn and sometimes are polished to extend life, generating lines on the surface that do not extend into any devices. (See SLIDE MARKS, HAIR LINES, BAG MARKS.)
DIE STRIATIONS: Lines arising on coins minted after a polished die.
DIE VARIETY: Some deviation from the intended design of a coin. PCGS lists important die varieties at PCGS CoinFacts. (See VARIETY.)
DIPPING: Using a chemical that removes a very small layer of metal on the surface. Coins that have been dipped have a grainy rather than luster appearance. (See CLEANING MARKS.)
DIRTY ROLLER MARKS: Fine, straight, parallel streaks caused by dirt, metal shavings, or grit getting caught in rollers that flatten planchets, leaving marks that can look like “woody” streaks on coins. (See WOODY.)
DISME: Archaic spelling of the denomination “dime.”
DOUBLE DENOMINATION: A coin struck with a pair of dies from different denominations
DOUBLE STRUCK: A coin struck correctly on the first strike but then struck again adding another portion of the same design to the original.
DOUBLING: Also known as hub doubling and double die, a coin that underwent a bounce on the die, leaving two images on the surface, as opposed to machine doubling caused by a loose die with little numismatic value. (See HUB DOUBLING, MACHINE DOUBLING.)
DRYER COIN: Coins that slip out of clothing and are tumbled with heat, removing the original edge so that it appears smooth. (See SPOONED COIN.)
E
EAGLE/DOUBLE EAGLE: A coin worth $10; doubled, $20.
EDGE: The surface between the coin’s faces, as opposed to rim. (See RIM.)
EFFIGY: The depiction of a person on a coin.
ELECTROTYPE: A coin made from a mold of a genuine coin coated with metal to create a forgery, especially with ancient coins.
ELONGATED: A coin that has been elongated or flattened and embossed with a new design.
ENCAPSILATION: Holdering or grading a coin. (See CERTIFICATION, HOLDERED, SLAB.)
ENGRAVER: A sculptor who creates the coin’s design.
ENVIRONMENTAL DAMAGE: A coin damaged by the place it was stored or the climate it was exposed to, often resulting in corrosion.
ERROR: A mistake in the production of a coin. For instance, a 1941 die was mistakenly used to produce a 1942 Mercury dime, resulting in an overdate error.
EXERGUE: A dedicated space at the bottom of a coin.
EXONUMIA: Tokens, medals, medallions and other non-monetary issues that look like coins but are not.
EXTRUSION STRIKE: A coin whose metal bulges into a gap during the striking process, creating an area of the die-struck design.
F
FACE VALUE: The amount of money written on the coin.
FANTASY PIECE: A privately made coin, not legal tender nor intended for payment, and also not considered counterfeit as it does not attempt to replicate actual currency.
FEEDER FINGER ERROR: Occurs when a metal finger, used to feed planchets into the striking chamber, malfunctions or gets jammed, resulting in marks or damage on the coin.
FIELD: The surface of a coin lacking any element of design/device.
FILED RIM: A coin with the rim intentionally smoothed or filed down, often confused with a rim ding and made to hide imperfections or for bullion theft. (See RIM DING.)
FILLED MINT MARK: Filled mint marks are relatively common, especially in Denver mint, and not considered a significant error or a major factor in increasing a coin’s value.
FLAN: Synonymous with planchet and blank, the metal upon which a coin is struck. Flan used more often with ancient coins. (See PLANCHET.)
FLIP: A cardboard coin holder with thin plastic window or a clear plastic holder used to preserve coins from handling and harm.
FLOW LINES: Uniform lines expanding from the center and indicating that a coin was struck rather than cast in a mold. (See CAST.)
FOURRE: A base metal counterfeit, often seen in ancient coins, made from a base metal core that has been plated with a precious metal.
FULL BANDS (FB)
FB MERCURY DIME: Showing the middle bands of the fasces are clearly separated with no breaks, scratches or marks in coins grading at least MS60.
FB ROOSEVELT DIME: Showing the lower and upper bands of the torch are clearly separated with no breaks, scratches or marks in coins grading at least MS60.
FULL HEAD (FH)
Showing three leaves on the head, ear hole must be present, and hairline distinct.
FULL STEPS (FS)
Showing a strong strike for coins grading MS60 or higher, with at least five unbroken steps visible on the reverse Monticello building.
GEM: MS-65 or better on the 1-70 Sheldon scale.
G
GLUE RESIDUE: Collectors in the 20th Century sometimes glued the reverses of coins so that they remained in the album or board.
GOLD: Element 79 on the periodic chart and its symbol is Au.
GRADE: Condition of a coin described with these designations: Poor (Po), Fair (Fr), About Good (AG), Good (G), Very Good (VG), Fine (F), Very Fine (VF), Extra/Extremely Fine (EF or XF), Almost Uncirculated (AU), Uncirculated (UNC), and Brilliant Uncirculated (BU). See PCGS photo below of a grader at work. (See SHELDON SCALE.)
H
HAIR LINES: Scratches or marks usually due to improper cleaning.
HENNING NICKEL: Francis LeRoy Henning manufactured counterfeit nickels dated 1939, 1944, 1946, 1947 and 1953, forgetting to put the P mintmark on the war nickel, which collectors most desire.
HIGH RELIEF: A coin whose devices are noticeably higher than normal, struck for that purpose. (See LOW RELIEF.)
HOLDERED: A certified encased coin. (See CERTIFICATION, SLAB.)
HUB: A metal object with a raised, positive image of a coin’s design used in the process of creating dies, which are then used to strike coins.
HUB DOUBLING: Duplication of a device or part of a device or legend due to misalignment of the dies at the mint. (See DOUBLING, MACHINE DOUBLING.)
I
IMPACT DAMAGE: Any physical damage that occurs from being struck or coming into contact with another object. (See: POST MINT DAMAGE.)
IMPAIRED PROOF: A damaged, cleaned or circulated proof coin that no longer is mint state. (See: PROOF.)
IMPROPER ALLOY MIX: A mix of different metals, or alloys, that deviates from the standard Mint production percent, sometimes resulting in a woodgrain surface. (See: WOODY.)
IMPROPER ANNEALING: An error caused when a planchet is incorrectly heated and warmed, exposing a layer of metal on the surface of a coin, as in this PCGS example:
INCOMPLETE PLANCHET: Flaw in the coin blank such as missing metal resulting in a clip or curved clip. (See CLIPPED PLANCHET.)
INCORRECT PLANCHET: A blank for one denomination mistakenly used in a strike of another denomination. (See PLANCHET.)
INCUSE: Devices that are impressed rather than raised on the surface of a coin, typically found in Indian Quarter and Half Eagles of 1908 through 1929.
INDENT ERROR: A coin struck when two planchets are in the coining chamber at the same time.
INSCRIPTION: The lettering or wording of a coin. (See LEGEND.)
INTRINSIC VALUE: The worth of precious metal in a coin. (See SILVER MELT, FACE VALUE.)
J
JEWELRY MARKS: Coins that have been placed in a bezel and then removed, leaving telltale marks.
JUGATE: Two busts or portraits facing the same direction on a coin.
JUNK SILVER: Coins without numismatic or collector value and worth only the spot price of the precious metal. (See SILVER MELT.)
K
KARAT: Measure of gold’s purity, marked with a K, as in 18K gold ring. (See GOLD, CARAT.)
KEY DATE: A rare coin by mintage, survival rate or condition, bringing high value premiums. Expand photo below for key dates.
L
LAMINATION ERROR/DELAMINATION: A portion of a coin’s planchet due to impurities of the planchet.
LAUREATE: Device or figure on a coin bearing a crown of laurels.
LEGAL TENDER: Coins that can be used still in commerce.
LEGEND: The inscription or motto of a coin. (See MOTTO.)
LETTERED EDGE: A design or inscription on the rim of a coin.
LINEAR PLATING BLISTER: A type of blister that appears as an elongated, raised bump on the surface of a coin, particularly on copper-plated zinc cents.
LONGACRE DOUBLING: Type of doubling that appears like a rounded, secondary image, often found on Indian Head cents and Seated Liberty coins and named after engraver James B. Longacre, said to have caused the error.
LOVE TOKEN: Inscriptions, symbols and initials signifying a romantic relationship etched on a smoothed side of a coin.
LOW RELIEF: A coin whose devices are not noticeably higher than the surface or field. An example is the low relief 1922 coin, distinct from the high relief of the 1921 Peace Dollar. (See HIGH RELIEF.)
LUSTER: The shine of a coin reflecting light on the fields.
M
MACHINE DOUBLING: Caused by a loose die and distinct from hub doubling (double die) or misalignment of dies at the mint. (See DOUBLING, HUB DOUBLING.)
MASTER DIE: A high-quality die (to preserve the design) used to create working hubs (positive impressions). Those are used to create working dies (negative impressions). (See WORKING DIE.)
MATED PAIR: A rare error in which two planchets are struck at the same time in the coin press, resulting in different errors.
MATTE PROOF: A sharp strike with a dull, granular surface. (See PROOF.)
MEDAL/MEDALLION: Resembling a coin, a medal commemorates a person, event, organization or occasion; a medallion is a larger version.
MILK SPOT: Caused when silver planchets are degreased with solvent not thoroughly removed before the annealing process, leaving white dots.
MILLED: Coins struck my machine rather than hammered or cast. Milled coins began in France using a water mill to run the minting press. Edges of milled coins usually have reeds or lettering. (See LETTERED EDGE.)
MINT: Where coins are produced.
MINT MARK: A letter or symbol indicating where a coin was struck. Note: On US coinage, denominations without a mint mark typically mean struck at the Pennsylvania mint.
MINT SEAL TOKEN: A commemorative item showcasing the Treasury Department’s official emblem and often found in mint sets (See MINT SET.)
MINT SET: Coins sold by year or occasion as manufactured by the U.S. Mint.
MINT STAPLE ERROR: A piece of metal that has fallen onto the die during the production process, leaving a raised image of the object.
MINT STATE: MS-60 to MS-70 on the Sheldon scale.
MISALIGNED COLLAR: A strike in which the die does not square up perfectly with obverse or reverse, resulting in a partial collar or mint error, usually not very valuable. Also known as “collar clash.” (See COLLAR.)
MOTTO: Inscription of a coin. (See LEGEND.)
MULE: A coin whose obverse and reverse are meant for different coins. The quarter below has a dollar reverse.
N
NGCX: A 10-point grading scale for modern coins 1982-present to supplement the 70-point Sheldon grading system. Note:10 is the top grade, equal to 70 on Sheldon. (See SHELDON SCALE.)
NO MINT MARK: Because there was only one mint in Philadelphia in the early 19th Century, no mint mark was used. However, the “P” mint mark appears on coins from 1942-1945. Beginning in1980 all of Philadelphia’s coins (except cent) have the “P” mint mark. The W-mint mark was used on America the Beautiful quarters in 2019 and 2020.
NOVELTY COIN: A magician’s coin with two heads or two tails.
NUMISMATIC/NUMISMATIST: The study of coins and a person who studies coins.
O
OBSOLETE: The design or denomination of a coin that no longer is being minted.
OBVERSE: Head’s side of a coin. (See REVERSE.)
OCCLUDED GAS BUBBLE: A trapped pocket of gas, usually air, forming an unbroken mass over an area of a coin, often confused for a bleb, which has lower irregular relief. (See BLEB.)
OFF CENTER: A misaligned strike wherein part of the design is missing. (See MISALIGNED COLLAR.)
OVERDATE: One number of the date repunched over a different number, as in 1942/1. (See REPUNCHED.)
OVER MINT MARK (OMM): One mint letter erroneously punched over a different mint mark, as in the 1938 D/S Buffalo Nickel. (See REPUNCHED.)
OVERSTRIKE: A new coin struck on a previously struck planchet. (See VISE JOB.)
OXIDATION: Tarnish on the surface of a coin caused by cigarette smoke, dampness, fumes or other element. (See VERDIGRIS.)
P
PAREIDOLIA: Tendency to perceive images in visual patterns, often leading to misidentification of coin errors.
PARTIAL PLATING: An error where copper plating solution doesn’t cover all of a zinc coin, like the cent shown below.
PATINA: The toning on the surface of a coin.
PATTERN: A coin with a new design that has not been released by the mint for commerce, a test die to view devices, and experimental die, perhaps to test a new metal or alloy. (Also known as “essai” coin.) Here is a pattern Morgan half dollar:
PIN SCRATCH: Occurring when stapling or unstapling a coin into or out of a flip, cardboard holder with thin plastic covering. (See FLIP.)
PITTED: A type of acid-like corrosion on the surface of a coin.
PLANCHET: A blank piece of metal where a coin will be struck. (See BLANK.)
PLATED: A coin dipped in silver, gold, copper or other metal to give the appearance of luster or value, with such coins as 1943 steel cents, 1883 five cents, and modern replicas typical targets.
PLATING BLISTER: Caused by heat and pressure expanding gas during the striking process due to a weak bond between the copper plating and zinc core. Note: Also called gas blister.
PLUGGED: A coin that had a hole in it, repaired with metal.
POCKET CHANGE: Circulating coinage with no collector value.
POCKET PIECE: A coin kept in a person’s clothing as a good luck charm, typically worn almost to basal state. (See BASAL STATE.)
POROSITY: A corroded coin exposed to elements or environment.
POST MINT DAMAGE (PMD): A flaw, crack or other damage that happened after a coin was released from the mint.
PRIVY MARK: A symbol appearing on a coin to honor a special occasion, as in the 75 anniversary of the end of World War II.
PROOF: Coins struck for collectors with mirrored fields and frosted devices. (See BUSINESS STRIKE, MATTE PROOF.)
PROOF SET: Proof coins packaged by year or occasion.
PROVENANCE: A term synonymous with pedigree to identify who owned a coin in its numismatic history
PUNCTUATED DATE: A die defect, such as a small mark or a comma-like line, that appears within the date of a coin and is valued as a mint error.
PVC DAMAGE: Flips made of polyvinylchloride can degrade and poison the metal of coins, usually leaving a green-like residue. (See VERDIGRIS.)
Q
QUICKSILVER: Another name for mercury, used as an ingredient in alchemy attempts to make gold.
R
RACKETEER NICKEL: An 1883 “No Cents” nickel that scammers plated and tried to pass off as a $5 coin.
RARITY: The scarcity of a coin due to mintage or survival. (See CONDITION RARITY, SHELDON RARITY SCALE, UNIVERSAL RARITY SCALE.)
RAW: A coin that has not been holdered.
REEDING: Narrow ridges on a coin’s edge to prevent clipping.
RELIEF: A device of a coin raised above the surface.
REPUNCHED: A variety of a coin whose date or mintmark seems double struck.
RESTRIKE: Coins minted with the original dies at a later date.
REVERSE: The tails side of a coin. (See OBVERSE.)
REVERSE PROOF: A coin whose fields are frosted, rather than devices and lettering. (See PROOF.)
RIDGE RING: A raised ridge that appears along the perimeter of the coin, near the rim, often associated with die deterioration.
RIM: Raised edge of a coin on the face sides (heads, tails). (See EDGE.)
RIM DING: Damage from another coin on the rim, usually occurring in bank or mint bags.
RING OF DEATH: A circular mark caused by a coin counting machine, also known as a “wheel mark.”
ROLLER MARKS: Parallel lines caused by a flattening process at the Mint during manufacturing and caused before the coin is struck, thereby not designating this as an error.
ROTATED DIE: A die that came loose in its recess and thus rotated out of standard coin alignment. (See COIN ALIGNMENT.)
ROUND: Typically, a one-ounce bullion piece, as distinct from a coin.
S
SCRIP: Paper money usually under a dollar produced by individuals or private organizations.
SEIGNIORAGE: The difference between the cost of minting a coin and the face value of that coin.
SERIES: All date and mint marks of a coin design or denomination.
SET REGISTRY: An application provided by holdering companies to register your coins according to denomination, providing values and rarities.
SHELDON SCALE: A numerical measurement from 1-70 describing a coin’s condition.
SHELDON RARITY SCALE: A popular rarity designation (R-1 through R-8) with low numbers being more common and upper numbers more scarce. (See UNIVERSAL RARITY SCALE.)
SILVER MELT: The value of silver in a coin without numismatic value. (See JUNK SILVER, FACE VALUE.)
SILVERING: A thin layer of silver wash on ancient coins meant to hide the base metal content or alloy.
SLAB: The plastic or case of a coin that has been graded and encapsulated. (See HOLDERED, CERTIFICATION.)
SLIDE MARKS: Lines left on the surface of a coin from sliding off the plastic cover of a coin album, such as Dansco albums. (See CLEANING MARKS.)
SLIDER: An almost uncirculated coin that has slight wear and looks uncirculated.
SMOOTHED: An alteration of a coin by whizzing, using a rotating wire brush to create a false luster, or heating to the point where the metal can be manipulated to hide flaws. (See WHIZZING.)
SPARK EROSION PROCESS: Coins altered by and counterfeit dies created by using sparks to change metal as purportedly was done in the creation of the 1959-D Memorial Cent with Wheat Reverse.
SPECIAL MINT SET (SMS): Coins with a matte-like finish issued from 1965 to 1967 during which production of traditional proof sets were halted.
SPLIT DIE: A rim to rim die crack. (See DIE CRACK.)
SPLIT PLANCHET: A coin that lacks devices and designs on one side with a grainy appearance due to a defective planchet. (See DEFECTIVE PLANCHET.)
SPLIT PLATE DOUBLING: Doubling on copper-plated zinc cents caused by the copper plating separating and revealing the zinc core.
SPLIT PLATING: A coin whose thin copper plating stretches too thin during the striking process, causing it to separate and expose the underlying zinc.
SPOONED COIN: Tapping edges of a coin until takes the shape of a ring. (See DRYER COIN.)
SPOT PRICE: The daily value of precious metals in the marketplace.
STRUCK THROUGH GREASE: A clogged die that strikes with a mixture of lubricant and metal dust.
SUNKEN DIE: Also known as die subsidence, a type of die error that occurs when a portion of the die’s striking surface sinks, resulting in a bulge that resembles heat damage.
T
TEST CUT: A deliberate cut made into a coin, often with a knife or chisel, to check if the precious metal is genuine or a fake.
TEXAS CENT: Created by smashing a penny inside pieces of leather, retaining the design and flattening the coin.
TILTED COLLAR: An improperly positioned planchet causing the edge of a coin being struck at an uneven level.
TOKEN: A privately produced coin that has no value in commerce. Here is a California Gold token, minted in 1970 with a faux date of 1852.
TOLERANCE: Low and high weight deviation levels for specific coins so that they fall within the U.S. Mint standards (i.e. Morgan dollar weight of 26.73 can be as low as 26.63 or as high as 26.82.
TRIME: An American coin with a face value of 3 cents minted from 1851-1873.
TRUNCATION: On a coin, typically the bottom cut-off part of a bust.
TYPE: A coin’s design, used to distinguish varieties, as in Type I and Type II of the 1956 Proof half dollar:
TYPE SET: One of each of the denominations of a particular coin. Also used for a slate of varieties, as in the 1982 cent.
U
ULTRA RARITY: A coin in which few exist or have survived. (See SHELDON RARITY SCALE, UNIVERSAL RARITY SCALE.)
UNCIRCULATED: A coin that has never been used in commerce. (See CIRCULATED.)
UNIFACE: A coin with the design on only one side, usually due to a mint error.
UNIVERSAL RARITY SCALE: A scale that measures degree of rarity, with lower numbers designing increasing scarcity. (See SHELDON RARITY SCALE.)
V
VAM: Refers to the differences between the dies used to strike Morgan and Peace dollar coins and an acronym for numismatists Leroy Van Allen and A. George Mallis, who cataloged the die differences.
VARIETY: Small deviations of a coin’s emblems, dates, mints, devices, etc., that sets it apart from the originally intended design.
VENDING MACHINE COIN: A coin that has been deliberately altered by shaving down edges to illegally trick a vending machine into accepting it for a higher value than it is actually worth.
VERDIGRIS: Oxidation of copper taking on a greenish or green/blue color eventually eroding and damaging a coin. (See PVC DAMAGE.)
VISE JOB: A coin that has been placed in a vice with another coin, imprinting devices and masquerading as a overstruck error. (See OVERSTRIKE.)
W
WAFFLE: A process used by the U.S. Mint to deface a coin so that it cannot be used for scrap metal, resulting in a coin that resembles a waffle or pancake.
WHIZZING: Removing a thin layer of the coin’s surface using a Dremel or similar device. This gives the coin false luster. Typically, devices will be worn and fields similar to uncirculated shine.
WIRE RIM: A coin without a rim, eventually replaced with a rounded rim, or collar, to prevent wear.
WOODY: A woodgrain appearance typically found on Lincoln cents, due to an improper alloy mix at the mint. (See IMPROPER ALLOY MIX.)
WORKING DIE: A die made from a master one used to strike coins. (See MASTER DIE.)
X
X-COIN: A type of crypto currency.
Y
YEAR SET: All denominations of a particular date.
Z
ZINC: An element on the periodical chart, 30, found in various minerals and often alloyed with copper to make brass.
ZINC ROT: Corrosion from moist air, humidity or packaging, transforming the zinc into zinc hydroxide.
