It’s one of those unbelievable stories that coin collectors dream about — a simple, everyday penny that could be worth a small fortune. Experts are once again warning Americans to check their loose change, because a rare version of the Lincoln cent — worth up to $336,000 — is still occasionally found in circulation.

The coin in question is the 1943 bronze Lincoln cent, a legendary minting error that happened during World War II. That year, pennies were supposed to be made from steel coated with zinc, as copper was being used for the war effort. But a few bronze blanks from 1942 accidentally made it into the presses, resulting in one of the most sought-after coins in U.S. history.

Only a handful of these 1943 bronze pennies are known to exist, and each one has fetched staggering prices at auction. One sold for over $336,000, while others have gone for anywhere from $150,000 to $250,000 depending on condition.

So how can you tell if you have one? It’s simple:

• Check the year — it should say 1943.
• Test it with a magnet — a real bronze penny won’t stick, but the steel versions will.
• Look for a reddish-brown color instead of the silvery tone of typical 1943 pennies.

If you think you’ve found one, don’t clean it — that can destroy its value. Instead, have it authenticated by a professional coin-grading service like PCGS or NGC.

Collectors call it the “holy grail” of U.S. coins — proof that sometimes, a forgotten penny can be worth more than a luxury car. So before you toss that spare change jar, take one last look… because that lucky penny might just change your life.