What this coin looks like (obverse, reverse, mint mark location, special features, etc.):
One major variety is the 1846/5 $10 Gold Liberty Head Eagle featuring a "6 Over 5" overdate. Some numismatic experts have discredited this variety. Although some (such as PCGS) still recognize the variety and places single quote marks around the "5" in their identification - such as: 1846/'5'-O. There is clearly an anomalous feature within the loop of the "6" and within the bottom half of the "6" as depicted by the arrows in the example image below. Not all numismatists agree that this is an underlying number "5" - but could be a die defect instead. Depicted below is a closeup example image of the 1846/5 "overdate" (Source of example images is courtesy of Heritage Auction Galleries):
Coin valuation chart: Typical coin prices, values and worth per grade or condition - in USD