The most unusual item for sale at next month’s U.S. coins Heritage auction isn’t really a coin at all. It’s technically a zinc nail whose center has been imprinted with the head and tail sides of a Roosevelt dime.

Mint errors that slip into circulation, like coins struck with the wrong dates or onto the wrong materials, are often hot ticket items at coin auctions. Thousands of rare coins will be hitting the auction block at the Heritage auction in Tampa, Fla. next month, but it’s this nail dime that’s been stirring up buzz. The item is expected to ultimately sell for around $10,000, and early online bids have already reached $7500

While this type of mistake is rare, it’s not unprecedented—in the late 1970s, a handful of U.S. pennies were struck onto nails. It’s also possible that this particular misprint wasn’t a mistake at all and was created deliberately by a rebellious employee. The nail dime is undated, so little can be said about the item’s history.

No matter how it originated, the dime is still expected to go for a pretty penny once it hits the auction on January 6. And as for whether or not the coin can be used as valid currency, the U.S. Mint told AP they had no comment.  

Heritage Auctions

[h/t AP]