While most collectable, not to mention valuable, coins are usually quite old, this more modern error quarter can be a fun ...

There's something to be said for collecting old coins. Some people do it for the fun of it or to have a cool story to tell.

Here are 20 rare state quarters worth additional value, according to Gainesville Coins, USA CoinBook and PCGS. Keep in mind that “error” coins — the ones primarily included on this list ...