When is a penny worth $1.15 million? When it is a rare experimental penny minted in 1792.
The unusual coin was auctioned off Thursday at the Renaissance Schaumburg Convention Center in suburban Chicago.
Officials with Heritage Auctions say Kevin Lipton of Beverly Hills, Calif., bought the penny on behalf of a group of unnamed investors. The winning bid was $1 million, but the investors also must pay the auction house's 15 percent commission.
Heritage Executive Vice President Todd Imhof says the coin is made with a copper ring that surrounds a small plug of silver, which was added to make the penny heavier.
Imhof says the coin was never actually put into circulation and only 14 examples of the coin are known to exist.