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Obverse of Washington Quarter/Sacajawea Dollar MuleReverse of Washington Quarter/Sacajawea Dollar Mule

The Spectacular (2000-P) Washington Quarter Dollar/Sacajawea Dollar Mule Error
Images courtesy of Heritage Numismatic Auctions


Everybody makes mistakes and the United States Mints are no exception.  The odds of producing billions of coins each year with no errors is simply too great.  Normally, error coins are caught through the usual quality control procedures but, occasionally, some of the mistakes get by the inspectors and enter the normal channels of circulation.  Some error coins may have been made deliberately, as their very existence is cause for suspicion.

The categories at right feature some of the most dramatic and important error coins that have ever appeared on the market.

Off-Center Struck Coins
Double and Multiple Struck Coins
Mated Pairs
Capped Dies
Wrong Metal/Wrong Planchet Errors
Bonded Coins
Spectacular Errors
Die Adjustment Strike
Proof Errors
Transitional Errors
Double Denomination Errors
Struck Fragments
Fold-over Strikes
Errors on Proof Planchets 
Dual Type