What this coin looks like (obverse, reverse, mint mark location, special features, etc.):
The 1873 Indian Head Cent (Penny) had 2 major varieties related to leading "3" in the 1873 date. The image depicted above is the 1873 "Closed 3" variety.
The difference between the Open "3" vs Closed "3" can be best identified by noticing the width between the central area of the number "3". The Closed "3" penny is narrow while the Open "3" is wider. The difference in width for the closed "3" vs open "3" is shown by the arrow as depicted in the example image of the coin below:
Coin valuation chart: Typical coin prices, values and worth per grade or condition - in USD