What this coin looks like (obverse, reverse, mint mark location, special features, etc.):
There were a few major varieties of the 1821 Capped Bust Dime. The two major ones deal with the size of the 1821 date on the coin. One variety had a larger date with larger numbers while one had a smaller date with small numbers. The difference between the 1821 Small Date vs Large Date Capped Bust Dime is depicted in the example image above.