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    

1955 Double Die Lincoln Wheat Cent { Key-date Error }1937-d Buffalo Nickel, 3-legger, Collectors Favorite Mint Error, * Free Shipping1856-s $20 S.s. Central America No Serif Spike F Gold Liberty Head Pcgs Au551795 Half Cent Interesting Inverted Die Clash In Denticles Below Date 100% Orig.Double Struck Jefferson Nickel Like You Never Saw Before Pcgs Ms661959 1 ¢ Double Struck Pcgs Ms-65 1984-p Roosevelt Dime Double Struck Take A Look2004 D Extra High Leaf Wisconsin State Quarter Beautiful Magnificent Rare Error1849 G$1 Small Head No L Gold Dollar Ngc Ms 621972 Double Die Lincoln Memorial Penny - Pcgs Ms65rd Red - Old Green Slab Holder1895-s Morgan Dollar - Very Fine1935 Ngc Xf45 Buffalo 5c - Doubled Die Reverse Fs-801 Ddr Rare In Xf+ Grades1916 Buffalo Nickel Off Center Take A Look2012-s 50c Silver (proof) Kennedy Half Dollar1885-cc Morgan Dollar Ms-65 Pcgs2010 Sac $1 Missing Edge Lettering Pcgs Ms-66 No Date Susan B Anthony Mint Error Pcgs Ms65 $1 Struck 35% Off Center1945-s Linc.1¢ Struck 20% Off-center 1812 Classic Head Large Cent, Large Date, G-vg Detail, Clipped Planchet1880-cc Morgan Silver Dollar Pcgs Ms-64+ Lqqk ~3 Old Unusual Odd Unknown Error Coins 1943d Copper Wheat Cent Trial Strike1853-o 50c No Arrows Liberty Seated Half Dollar *beautiful Detailed Early Coin 1895-o Morgan Silver Dollar Xf-45 Pcgs1918/7-d Overdate * Pcgs G04 * Buffalo Indian Head Nickel 5c Rare $1,250++ ErrorOff Center 1945 Cent Lincoln Penny 50+% @k-7:30 Uncertified Unc Red/bn1996 Huge Nickel Size Broad Struck Error Roosevelt Dime Gem Bu Coin O/c Bs 19 Nr1887-s Morgan Silver Dollar Ms-64 Pcgs1937-d Buffalo Nickel, 3-legger, Highly Desired Mint Error, ** Free Shipping!Pcgs 1c 1999 Lincoln Ms64 Red Vss Certified "wide Am" Fs-901 'rare" St. $99.99Pcgs $1 1979 P Ms66 "wide Rim" Pcgs Top Pop Only 351 Pcgs Price $130 Start $0.99 1967 25¢ Broadstruck & 15% Straight Clip Pcgs 1875-s/s Twenty Cent Piece, Sought After Mint Error, ** Free Shipping!5 Off Center Washington Quarters 1976 To 1980, All Nice--no Reserve1879-cc Morgan Silver Dollar Ngc Vf25 Error Coin Capped Cc Vam-3Mint Error 10% Off Center Strike 1944 Bu Mercury Dime1955 1c-50c Proof Set Box (proof) Some Nice Rainbow Toning Ike $1 Type-ii Clad Planchet-ngc 1894 Unc $10.00 Gold Eagle1901 Indian Head Cent Off Center Take A Look1813 Capped Bust Half Clashed Die Obv. & Multiple Die Breaks Obv & Rev. Ex.fine2009 Sac $1 Missing Edge Lettering Pcgs Ms-66 1989 1 ¢ Triple Struck Pcgs Ms-65 Red 1935 Buffalo Nickel Vf20 Pcgs Ddr Fs-801 Double Die Reverse Cherrypicker Variety1941 Jefferson Nickel Off Center Take A Look1983-p Washington Quarter Uncirculated Off-center Error 25c Philadelphia1807/6 Overdate Draped Bust Large Cent - Aa11943-s Lincoln Cent Off Center Take A Look1884-s $20 Liberty Gold Double Eagle Au-50 PcgsNd 10¢ Roosevelt Clad Double Strike, Saddle Struck Error Iii-l-8 Ms (8 Photos)1839 Booby Head Large Cent -cud Error- Extremely Fine1970-d Double Struck Die Cap Cent Bu1878-cc Ngc Silver Dollar Rotated Dies **mint Error** Au Details Ngc Nice!1846 Braided Hair Large Cent With Rim Cud Mint Error Extremely Fine+1829/1827 Bust Half Dollar Ngc Vf25 O-102 Overdate. Nice Collector Grade 2008 $1 J.q. Adams Missing Edge Lettering Pcgs Sp-65 1801 Three Error Rev. Early Large Cents Draped Bust Cent (es2004 $1 American Silver Eagle Ngc Ms69 Mint Error Obverse Struck Thru1805 Draped Bust Large Cent Clipped Planchet (es1972 Lincoln Cent Double Die Obverse, Blazing Red, Us Error CoinPcgs 25c Double Slab Sc 2000 D & P Obv/rev Clad Layer Missing Ms64 St. $199.99