Loose change sitting in a drawer or hidden between couch cushions might seem worthless — but one small penny could be worth a fortune. Among everyday coins, the 1943 Bronze Lincoln Cent is one of the rarest and most valuable discoveries in U.S. coin history. Because of a wartime mistake during World War II, this tiny copper coin has sold for as much as $336,000 at auction — and experts believe a few could still be hiding in circulation today. In 1943, the U.S. Mint stopped using copper to make pennies because the metal was needed for wartime equipment and ammunition.

Instead, pennies that year were made from zinc-coated steel, giving them a shiny silver appearance rather than the usual copper color. However, during the busy production process, a few leftover bronze blanks from 1942 were accidentally used to mint some 1943 pennies. These rare bronze coins quietly entered circulation without anyone noticing at first.

Collectors only began discovering them several years later. When the first examples appeared in 1947, coin enthusiasts across the country started checking their spare change, hoping to find one of the mysterious error coins. Over time, the 1943 bronze penny became legendary in the world of coin collecting. Fewer than 20 authentic examples are believed to exist today, making them incredibly valuable.

Experts say there are a couple of simple ways to check if you might have one. A genuine 1943 bronze penny will not stick to a magnet, while the common steel version will. The rare coin also has a warmer reddish-brown copper color instead of the silver tone of steel pennies. So before you ignore that old jar of coins or the change in your pocket, take a closer look. One small penny from 1943 could turn ordinary pocket change into an extraordinary discovery.