Copper Lincoln cent, with a 1st strike mirror brockage obverse, and is a clashed cap strike. The error occurred when a uniface die cap struck the reverse die, creating raised design in the center of the die cap. The cap then struck this coin, resulting in a coin with no design anywhere except in the center of the coin. A good example for showing a clashed cap strike because there is such a strong contrast between the central brockage and no design around the outer parts of the coin.

PCGS MS-64 Red/Brown