PCGS 1955-S wheat cent struck on a silver Roosevelt dime planchet. The coin weighs 2.5 grams, and is silver. Additionally, it is smaller than a normal cent.
The error occurred when a silver dime planchet was fed into a press that was striking cents and was struck, resulting in a coin with the design of a cent but the planchet and metal of a dime.
Scarce (estimate 5-8 known.)