Errors on the State Quarters 
By Victoria Stone Moledor

If you believe you’ve found a state quarter that doesn’t appear normal, compare your coin with the photographs and descriptions of the following minor and major error coins.

Die Polishing

The first minor error Coin World saw on the quarters was heavy die polishing.  On the Delaware quarter, this might be seen on the reverse ("tails" side) under the belly of the horse and in the fields around the horse. Die polishing appears on the coin as raised lines of varying thickness and can appear on all circulating coins, not just the state quarters.

Mint technicians constantly spot-check the quality of coins pouring out of the presses. When they notice a problem on the dies, they will turn off the press and either replace the dies or polish the die to remove signs of the problem. Such problems can include a die clash, a die break or worn dies. A major problem will force removal of the die or dies. If the effect is minor and shallow, the technician will buff or polish the surface of the die in order to remove the effect.

Overzealousness in polishing will not only remove the effect but cut deep grooves into the surface of the die as well. These grooves translate to raised metal or lines on the coin.

Some of the polish marks seen on the State quarters have been quite severe, which is surprising since die polishing marks of that depth and size in recent times have not been so common. Die polishing, however, is still considered a minor error that does not add to the premium value of the coin.

Filled-Die Errors
Filled-die errors cause elements of a coin’s design to disappear. Some are severe enough to obstruct almost the entire die, while some are localized and obstruct only a small portion of the design.

The Mint is a production facility with dirt on the floor, dust in the air and grease oiling the high-speed machinery. It’s not difficult to think that some – or a lot – of grease and dirt could end up on the dies. In fact, filled-die errors are common, though those that feature a major obstruction of the coin’s design are considered desirable.  Most filled-die errors are common and do not add a premium value to the coin.

One of the first State quarter errors reported to Coin World was the "FIRST STAT_" error, in which the final E of state on the reverse ("tails" side) is missing on the Delaware quarter. A small bit of grease and/or debris compacted into the E to form this error. A die imparts its design on the surface of a coin because the pressure of the strike forces the metal up into the die. A die looks like the exact mirror image of the coin it is going to strike, so the words, numbers and portrait busts are set into the surface of a die. If anything fills into those recessed areas, when the die tries to strike a coin, the metal in the coin will not flow into the areas that are filled or clogged. Therefore, the coin will not show any details in that area.

Filled-die errors are known on all the issued State quarters.  They are very common and collectors should be wary of paying a premium for them.

An unusual filled die error involves the collar die (the circular die that creates the reeding around the edge of the quarter). A clogged collar die creates a coin with only partially formed reeding on the edge. Filling can occur on any portion of the coin.

Sometimes coins are found with little or no details at all. This could be a filled die error or it could be a major striking error.

Die Crack Errors
Die crack errors appear on coins as lines of raised metal that sometimes run to the rim (the raised border encircling the outer limits of each side) of the coin. They occur when a die cracks under the stress of striking coins. The metal of the coin flows into the crack during striking, forming the line of raised metal. Sometimes a thin die crack can grow into a chunky-looking line as other small pieces of the die fall out along the crack.

Cracks have been reported on the obverse ("heads" side) and reverse ("tails" side) of every State quarter.  Larger, clearly visible cracks are more desirable than smaller ones, but a die crack still does not add significantly to the value of coin.

Die cracks are common on quarter dollar coins and, in fact, are the number one reasons that dies are retired from service at the Mint. Because of the short amount of time in which each state’s commemorative quarters will be struck (about 10 weeks) it is unlikely that the Mint will streamline the design of each quarter’s dies in order to prevent them from cracking. Even with their propensity to crack, quarter dies can still strike hundreds of thousands of coins before they are retired.

Die Chips
Die chips show up on the surface of a coin as a raised lump. Many have been reported on the State quarters and are considered minor, common errors. Their cause is similar to that for die cracks – a small chip of metal breaks away from surface of the die, creating a void that coinage metal flows into during striking.

Major Striking Errors
Any one of the errors discussed in this section could occur on the State quarters, except for doubled dies and repunched Mint marks (RPM) varieties, which are die varieties. Because the Mint no longer employs the methods that made such varieties possible, it would be highly unlikely (if not impossible) that either variety would be found on any of the new quarters. A find suspected of being either a doubled die or an RPM error should be scrutinized as possible mechanical doubling.

Finding a major error in circulation is unlikely, though possible. Unless the error is easily identified, one must consider the coin was damaged or perhaps altered to look like a valuable error.

What's it Worth?
As a rule of thumb, minor, common errors usually do not bring a premium, though many collectors choose to add them to their collections in order to have representative examples.

Collectors are advised to exercise caution when purchasing minor error coins from dealers or online auctions.  Many collectors have overpaid for errors that are quite common and easily found in circulation.

Major errors are highly sought after and authentication is recommended. Some dealers perform authentication for free; others do not. It is wise to contact any source before submitting a coin for authentication.

For an opinion about an error coin’s value, consult an error coin dealer. The names and addresses of error coin dealers can be found within the pages of Coin World Magazine.