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    

1879-cc/cc Morgan Silver Dollar, Capped, Vam-3 Filled "g", Choice Bu++ Key Date!50c Nd Kennedy Half On 3.1 Gram Cent Planchet Au1937-d Buffalo Nickel, 3-legger,highly Desired Choice Au++ Key Date Mint Error!1942/1 Mercury Dime, Highly Demanded Xf++ Key Date Mint Error, ** Free Shipping!1857 1c Flying Eagle Cent Doubled Die Obverse Ddo Error W/ Broken Wing Unc Rare!1950 1c-50c Proof Set (proof) In Plastic Holder UncirculatedNgc 1c 2000 Lincoln Cent Struck On 2000-p Dime Planchet Ms-672012 25c Hawaii Volcanoes Np 5 Oz Silver Pcgs Ms69pl America The BeautifulPcgs Rare 1937-d Au55 3 Legged Error Buffalo Nickel With Nice Eye AppealPcgs Au58 1937 Off Center Buffalo Nickel Mint Error Great Eye Appeal1999 Georgia 25c Multiple Struck 40% Off Center Pcgs Ms65 *no Reserve*1955 Double Die Obverse Lincoln Wheat Cent AuNgc 1c Lincoln Cent Struck 70% Off-center Mint Error Gem Bu Rb1917-d Lincoln Cent- Struck 10% Off-center, Rusted Reverse Die Anacs Au582016 America The Beautiful Quarters Proof Clad Set Packing Error1984 Ddo Lincoln Cent Memorial Penny Red, Doubled Ear, Solid Gem Bu++ Mint Error1955 Double Die Lincoln Cent **ngc Graded Au58**1966 Silver Sms Kennedy "no Fg" Pcgs Sp 66 * Pcgs Value $675 *1c 1999 Lincoln Cent 2-coin Mated Pair Off-center & Indent UncNgc Huge Die Break On Jefferson Nickel Mint Error Great Error Type Cud1799 $1 Draped Bust Dollar1980-p 5c Jefferson Nickel Struck On A Cent Planchet *no Reserve*1958 Jefferson Anacs Ms 64 Improper Annealed Planchet Lot / 5 Coins2004-d Wisconsin Quarter 25c Error Extra Low Leaf Ngc Ms 66 Nors2000-p 25c South Carolina Mint Error Struck 20% Off Center Ngc Ms66 *no Reserve*1995 Double Die Obverse Lincoln Cent Ngc Ms 67 Red!!!1967 Double Die Washington Pcgs Sp 67 Ddo Fs 101 (026.5) * Pg $400 - Rare *25c 1985-p Washington Quarter Double-struck 2nd Strike 93% Off-center Unc2016 America The Beautiful Quarters Proof Clad Set Packing Error2012 25c Denali Np 5 Oz Silver Pcgs Ms69pl First Strike America The BeautifulLot Of (3) Pcgs Ms64/65rd Brockage Double Struck B/s No Date Lincoln Mint Errors1944 Off Center Broad Struck Mercury Dime Gem Bu. Make An Offer{bjstamps} Wheat Cent Struck Through Capped Die Lincoln Mint Error1959 Jefferson Anacs Ms 64 Improper Annealed Planchet Lot / 5 Coins1990-p Kennedy Half Dollar Struck 10% Off Center Mint Error Coin Ms66 Ngc K-6 NrLincoln Memorial Cent 1c Capped Die U.s. Mint Error - No ReserveGorgeous Toned Uncirculated Lamination Error 1881 Indian Head Cent 1c Penny 1979 Kennedy Off Center Struck Error Half Dollar Coin No Reserve1971-d Eisenhower Dollar Ngc & Cac Ms-65 "friendly Eagle Variety" Fs-901 Ike Fev2000 Huge Mushroom Broadstruck Brockage Lincoln Cent Mint Error Super Eye Appeal1999 Delaware Statehood Washington Quarter 25c Cent U.s. Coin Major Off Center1814 E/a Capped Bust Half Dollar Problem-free Original Rare Coin E Over A Error1979 Washington Quarter Huge Broadstrike Gem Bu With No Reserve!2007 George Washington $1 Coin Ms64 Mint Error (missing Edge Lettering)2007 Icg Ms64 Washington Dollar $1 Missing Edge Lettering Error Mel$1 1979-p Susan B Anthony Large Uncentered Broadstrike Au1c 2010 Lincoln Cent Struck 5% Off-center UncNgc Ms 65 2007 Washington Dollar Mint Error Missing Edge Lettering B864Error Coins: Four (4) Lincoln Cents Struck Off-center1941s Lincoln Wheat Cent Nice Reverse Cud Error1955/55 Double Die Lincoln Cent Au+/unc Details **great Color**tone.Pcgs Ms66 2001-p Mint Error Sacagawea $1 Experimental Rinse - No Reserve1905 V-nickel Struck On Tapered Planchet With Wire Rim Choice Au+ No Reserve!2007 Ngc Ms64 Washington Missing Edge Lettering Dollar Mint ErrorError Cents-lot Of 5 Different Off Center Lincoln Memorial Cents - Nr! -z26dxxx1996 Huge Nickel Size Broad Struck Error Roosevelt Dime Ch Bu Coin O/c Bs 126 Nr1880/79-cc Reverse '78 Pcgs Ms64 Mint Error/crescent Rainbow Toned MorganIcg Ms64 Huge Broadstruck Jefferson Nickel Mint Error Awesome Eye AppealError Coin: 1906 Indian Cent 1c With Doubled Date Ms61 Bn (ngc)1985 P Washington Quarter 50 % Off Center,high Grade,mint Damage Us Error Coin