This is a rare one-cent coin made of copper.

It was found in Massachusetts in 1947 and there are less than twenty left in the world.

During World War II pennies were supposed to be made of steel to conserve copper, but these were made by mistake.

The penny is up for auction right now, the current bid is at $120,000 but it could be worth millions.

A similar penny sold for 1.7 million dollars in 2010.