The combination of "copper" and "penny" might not seem like the best formula for valuable coins considering that you can find higher denominations in gold and silver. But finding the right copper ...

Coins aren't necessarily worth their face value, with some worth more than their cost of production and the penny famously ...

One one/hundredth of a dollar. A shiny bit of copper. A kid’s treasure found on the ground. The once proud but now lowly ...