What this coin looks like (obverse, reverse, mint mark location, special features, etc.): The 1873 Doubled Liberty Indian Head Cent (Penny) is one of the rare and valuable doubled die errors. The best way to identify this coin is to notice the prominent doubling of the word "LIBERTY" within the Indian headband as depicted in the example image of this coin above. Source of example image is courtesy of Heritage Auctions.
Coin valuation chart: Typical coin prices, values and worth per grade or condition - in USD