This is the only known Indian Head Cent struck on a Half Dime planchet for the entire series. There is an 1859 Indian Head Cent struck on a previously struck Half Dime.
Indian Head Cents struck on wrong planchets are very rare. This major mint error was struck prior to 1874 since Half Dimes were produced through 1873. A Half Dime planchet was positioned in the collar over the reverse die with a Cent planchet on top. Both of these planchets were struck by the hammer die containing the Indian Cent obverse design. The other coin from this pair would be an Indian Cent with the obverse design, but the reverse would have an indent from this piece. It is in choice mint state condition.