Generally speaking, there are two extremes in U.S. coin collecting. The first is to search for that Holy Grail coin in great condition, such as an 1856 gold Double Eagle that was minted in New Orleans and is graded AU-55, or a 1873 Morgan silver dollar, minted in San Francisco and graded MS-65.

People who love error coins are at the opposite end of the perfection spectrum, though they often pay top dollar for their treasured damaged goods. Errors are coins that didn't turn out quite as the mint intended, with clipped edges, overstruck dates, and quirky imperfections.

One of the many things that makes error coins so interesting is that they encourage the coin collector to become knowledgeable about the minting process itself, since all error coins are the result of something going awry at the mint.

At the top of the error pyramid are hub errors. The hub is the piece of hardened steel that is used to create a die, which is the metal punch that delivers a coin’s design onto a blank, or planchet. The design on the hub is the same as that on the coin, but the die is a mirror image, which means it transfers a correctly oriented image onto the final coin.

Until recent advances in minting technologies, it had taken two, three, and sometimes four strikes of a hub onto a heated die to successfully transfer the hub’s image. That left a lot of room for error, the most common of which occurs when the first and second strikes of a hub on a die are not perfectly aligned. In these cases, a doubled die is created, resulting in a coin whose elements repeat.

In rare cases, a double denomination can be created, such as in the case of the 11-cent denomination. Struck coins are sometimes transported from coining presses in bins that are later used to transport planchets. In this case, a bin full of struck dimes was reused to transport penny planchets. A few dimes that had become stuck at the bottom of a bin were struck again as cents along with all the planchets. The resulting 11-cent double denominations are larger than dimes but smaller than pennies. Coins that have the most detail are generally the most expensive, but collectors should mis-merit the value of a coin that's not perfectly round.

Another classic example of a doubled-die coin is the 1955 Lincoln Wheat penny, which some experts refer to as an error but others call a variety because so many of them made it into circulation. When the doubled die for this coin struck the obverse, or face, of the planchet, doubling occurred on the date and legend. As a result, the coin looks oddly out of focus...

Since the mistake was not caught until the coin was in circulation, no one knows for sure how many were made—just under 331 million Lincoln Wheats were minted that year, but only 15,000 doubled examples are known to exist. Whatever their number, the coin is credited with igniting an interest in error coins, as well as being a favorite target of forgers.

For collectors, only Lincoln Wheats with clearly defined doubling are considered valuable. For example, a coin with less pronounced doubling, known as a “poor man’s doubled die,” can be picked up for under a quarter, while coins whose doubling is clear and crisp sell for $1,000 and up.

Worn-out dies are also a problem. If the die is cracked, those cracks will also appear on a coin. Similarly, if a small section of the die has broken off, then a like-sized section of the coin will remain unstruck. This frequently happens along the edge of a coin and is referred to as a cud.

Even if the die is not compromised, many things can go wrong when it strikes a planchet. One relatively common occurrence is a broadstrike error, which is when the collar die (the punch that imprints the planchet with the design on the coin’s edge) fails to strike the coin at all, leaving it without any edging and a flattened-out center image.

Sometimes a die will strike a planchet wildly off center. In these situations the die is not the culprit; rather, there was a problem with the way in which the planchet was moved into position in the press. In extreme cases, an off-center coin will remain in the press to be struck a second time or more. In general, coins with multiple errant strikes are more prized by collectors than those with only one.

One of the most intriguing types of errors is a coin that has been struck properly but onto a clipped planchet, which is created when something is out of whack with the machine that stamped them out in the first place. For example, the machine stamps out a row of planchets too close to the one above it, the resulting bad blanks will look like someone took a bite out of them.

Planchet errors are also caused by stamping too close to the edge of the planchet’s source sheet metal, producing a blank whose otherwise perfect circular shapes are interrupted by straight edges on one side.

While production practices at U.S. Mints have improved in recent years, thus eliminating many of the most common historical errors, contemporary coins have not been immune to the occasional mistake.

For example, a crack in the die used to strike the reverse of the 2009 Formative Years Lincoln cent, which depicts the future president taking a break from chopping wood to catch up on his reading, can be seen at the bottom of the coin, through the second “U” in “Pluribus,” and up into the young man’s boot.

Because the crack resembles a bootstrap, this error, which may be widespread enough to be considered a variety, is known as the Bootstrap Lincoln Cent.

Even stranger are the die flaws that produced three different types of Wisconsin state quarters, all from the Denver mint, in 2004. The variations appear on the coin’s reverse and affect the number and orientation of the leaves on an ear of corn.

In the normal coin, the ear has a leaf on the left that arcs up and then down to the left. In a variation of that coin, there appears to be a second leaf below that one, rising out a wheel of cheese that sits below the ear of corn. A third 2004-D Wisconsin quarter shows that same extra leaf, only this time it is bent down and to the left. Inexplicable.

Finally there are so-called blundered dies, which refer to dies that were simply made incorrectly—unlike a doubled die, a blundered die suggests human rather than mechanical error. The most famous example of this sort of error is the 1982 dime, which was minted in Philadelphia but failed to identify itself with the “P” mint mark. An estimated 14,000 to 15,000 of these error dimes made it into circulation, which makes it a popular coin for many collectors.

About our sources | Got something to add?

▼ Expand to read the full article ▼

Best of the Web (“Hall of Fame”)

Legendary Coins and Currency

Legendary Coins and Currency

This online exhibition from the Smithsonian's National Museum of American History is a great way to get an overview… [read review or visit site]

Society of U.S. Pattern Collectors

Society of U.S. Pattern Collectors

Home to the Society of U.S. Pattern collectors, this well-organized site provides in-depth information on pattern c… [read review or visit site]



Clubs & Associations

Other Great Reference Sites

Most watched eBay auctions    

Complete Pcgs Ngc Carson City Morgan Dollar 1889cc 1893cc 1879cc $16,000 RetailRare Usa, $20 Double Eagle, Ddr Double Die Reverse, 1891-s Gold Coin AuPenny Roll #6 { 1972 Double Die Lincoln Memorial Cent & 1911-s Wheat } New Batch2008 W Reverse 07 American Silver Eagle - Ms70 Early ReleaseRare Usa, $1 Dollar, Ddr Double Die Reverse, 1889 Gold Coin [only 28950 Minted]1955 Pcgs Geniune Cleaning Au Details Double Die Obv Usa Copper Lincoln Wheat 1c2011-w 1 Oz Proof Platinum American Eagle (w/box & Coa)1922 No D 1c Lincoln Cent Strong Reverse Die Pair #2 Vf Very Fine Key Error!1972/72 Ddo Lincoln Cent Memorial Penny, Doubled Die Obverse, Highly Desired!1952 Washington Quarter Ngc Pf67 Superbird Variety. Super Clean, Light Cameo!1885-cc Morgan Dollar Ms-64 Pcgs1944-d 50c Walking Liberty Half Dollar Hand Cut "aw" Ngc Ms64 *error Coin*1795 Large Cent, Liberty Cap, Clipped Planchet, Mint Error! ** Flowing Hair!1837 10c No Stars Large Date Liberty Seated Dime1836 H10c Capped Bust Half DimeMorgan Silver Dollar 1887 P Pcgs Ms 63++ Old Rattler Toned Beauty Vam Die Clash2012-p 5 Oz Silver Atb Denali (w/box & Coa)1944 10c Mercury Dime - Mint Error - 25% Curved Clip - Ngc Ms632012 5-coin 5 Oz Silver Atb Set (elegant Display Box)1. A 2015 P National Parks State Quarter Kisatchie La Struck Off Center & Clip1972 Double Die Obv Lincoln Cent Ms64 Rb Ngc2010-p 5 Oz Silver Atb Hot Springs (w/box & Coa)No Date Jefferson Nickel Mint Error Full Brockage & Huge B/s Pcgs Graded Ms 641873-s H10c Liberty Seated Half Dime1984 Doubled Die Error Lincoln Cent Vintage Pcgs Ms67rd Double Ear B8511972-d Eisenhower Dollar Error, Ike, Large Strike Through, Xf-au, True Auction2007 Us Presidential Dollar $1 - George Washington - Pcgs Ms65 - Mint Error1857 G$1 Mint Error Pcgs Genuine Bent- Au Details Struck 10% Off Center 2014 Doubled Die Ddo Lincoln Cent "a Big One"!!!!7. Wrong Metal Error 1979 Lincoln Cent No Clad 2.6gr Struck On Type 1 Foreign ?1999 Delaware Quarter 65% Off-center Ngc Ms 65No Date Lincoln Cent Mint Error Reverse Die Cap Ngc Graded Ms 66 RedStrong 1882-o/o Morgan Silver Dollar $1☆uncirculated New Orleans Mint Nice ErrorRare 1964-d Jefferson Nickel Error - Struck On Lincoln Cent Planchet - Ungraded1999 P Connecticut State Quarter Off Center Error Coin - Uncirculated - Bu/ms1972 Lincoln Cent Double Die Obverse, Early Strike, Rb, Us Error Coin2004 Jefferson Handshake Nickel - Double Die Obv. Error Fs-101 - Ngc Ms 642003 $1 Silver Eagle Ngc Ms69 Mint Error American Bullion Reverse Struck Thru1881-cc Morgan Dollar Bu (gsa)1999 Large Mushroom Shaped Broadstruck Indent Lincoln Cent Error Anacs Ms64rbPenny Roll #9 { 1972 Double Die Lincoln Memorial Cent & 1928-s Wheat } New BatchDdr #1 1970-s Proof Washington Prime Doubled Die - Nice Bold ScarceError Coin Lot - (40) Total Coins Collection - Many Have Errors Identified1883 No Cents Liberty V Nickel Broadstrike Us Mint Error Coin Xf1873-1878 Trade Dollar - Good12. A 2007 Montana State Quarter Die Adjustment Strike Left Weak Strike Showing1989 "no P" Washington Quarter Error1881-s Morgan Dollar Ms-66 Pcgs13. A 1999 P Susan B Anthony Dollar Struck Off Center Error - No Reeding5. A 1946 P Lincoln Cent Struck With An Elliptical Clip Error - Tough Find2004-d Wisconsin Extra Leaf LowError No Date Icg-ms60 Blank Silver $1 Dollar Size Id# H179Huge Coin Lot Us Error Coins Rare Tokens 1909 Vdb Us Cent Unique Coins 1823/2 10c Small E's Capped Bust Dime Fine Good Date1879-s Morgan Dollar Rev Of 78 2008 Van Buren Presidential Dollar ~ Ngc Ms66 ~ Missing Edge Lettering Error ~1999 D New Jersey State Quarter Double Clipped Planchet Error Coin - Bu/ms - 25c(94) 2015-p Homestead Ne Error Quarters 004 "best Of Variety", 043, 051, 0531882 $5 Gold Liberty Head [g119]2010-p 5 Oz Silver Atb Yosemite (w/box & Coa)