A COIN in your spare change could be worth thousands of dollars

input: A COIN in your spare change could be worth thousands of dollars, so long as it has a particularly unique error.

A COIN in your spare change could be worth thousands of dollars, so long as it has a particularly unique error.

Keep an eye out for pennies and dimes, specifically, as the rare mistake involves both American cents.

Since the United States Mint first started producing coins in 1793, special versions minted by accident or on purpose have been highly sought after by collectors.

They also often sell for top dollar at auction.

One of the most infrequently seen errors on coins is known as a "mule."

It refers to when one coin is accidentally struck with another, either on one or both sides.

This happened several years ago with a 1943 Lincoln penny.

While striking on the front showed former President Abraham Lincoln and the date, along with the other signature notations like "In God We Trust" across the top, it was very clearly on top of a dime planchet.

That meant the coin itself was completely silver, intended to be a 1943 Mercury dime but with the accidental penny striking instead.

The striking itself wasn't perfect either, with the date muddled and off-center, as the Mint employee may have realized mid-strike that it was incorrect.

While the error itself added serious and "brilliant" value, the 1943 Lincoln penny on top of a Mercury Dime was also graded MS (Mint State) 62 by the Professional Coin Grading Service (PCGS).

Grading Standards for the PCGS go up to 70, meaning that the coin in question was in nearly excellent condition.

Error and condition combined, the coin sold for $28,750 with Heritage Auctions.

Not many others have been discovered with as significant a mule as this one.

However, if you're looking for the same exact version with the penny on the dime, it should stand out among the other coins with the clear mismatching of the penny on the dime.

Other versions with the same muling in a more subtle fashion have gone for even more money at auction.

Rare coinsYou may be holding something valuable in your wallet. Check out these articles on rare coins to see if you may have a treasure hidden deep in your pockets.

PENNY POWER

For example, a penny that had the correct obverse (heads) side with Lincoln on the front, and the reverse (tails) side featuring the Roosevelt dime backing is valuable.

A version just like that sold for $114,000 at auction earlier this year.

Almost all of the rarest known muling errors involve pennies.

They include four 2001-D Lincoln cents, the 1999 Lincoln cent, the 1993-D Lincoln cent, and the 1995 Lincoln cent, according to Heritage Auctions.

Experts discovered that the four 2001-D mules were struck together on the same day, using the same die pair, on the same press.

QUARTER QUALITY

Another mule error involving a 2000 Sacagawea one-dollar coin also sold for over $88,000.

Only 12 versions of the one-dollar coin remain in Fort Knox.

The mistaken version had the quarter strike for the same year, with the obverse side featuring former President George Washington.

It was also completely gold, as the 2000 Sacagawea one-dollar coins were made.

A Double Eagle coin also recently sold for a whopping $7.2 million.

There was even a special Liberty nickel that went for $4.5 million.