Some of the rarest and most valuable coins in U.S. history owe their worth to minting errors that slipped through unnoticed. Coins like the 1943 Copper Penny, struck in copper instead of wartime steel ...

Imagine grabbing coffee and getting a dime as change. You pocket it without thinking, maybe check your phone, and move on with your day. That same coin, sitting in your wallet right now, could be ...

When that coin crossed the auction block, it realized $15,862.50, a figure that has since become shorthand among collectors for how extreme mint errors can rewrite the value of a modern quarter. The ...