Most people mistake them for quarters and toss them in a jar. That's exactly why Susan B. Anthony dollars are one of the most interesting coins the US ever minted.

Quick history: In 1979, the US Mint put a real woman on a circulating coin for the first time. Susan B. Anthony — the suffragist who was arrested for voting in 1872 — became the face of the new dollar coin. It was controversial, it was polarizing, and it only lasted a few years (1979-1981, then a brief return in 1999).

Why collectors care:

• The 1981-S is a proof-only issue — never entered circulation

• The 1979-P "Wide Rim" (or "Near Date") variant is a genuine key date

• Even common dates in uncirculated condition are getting harder to find

Why they matter beyond collecting: These coins represent the first time a non-mythical woman appeared on US currency. Before SBA dollars, the only women on coins were Lady Liberty. That historical weight makes them more than just metal.

If you've got a jar of "weird quarters" at home, take a second look. You might be sitting on something worth knowing about.