Despite its name, the Mercury Head dime does not actually depict Mercury.
First minted in 1916 and designed by Adolph Alexander Weinman, the mercury dime actually features a portrait of Lady Liberty on the obverse, wearing a winged cap. (The mythical Mercury was actually male, and had wings on his feet.) Since the resemblance was to Mercury, the name "Mercury Dime" or "Mercury Head Dime" was commonly used, and eventually stuck. The portrait of Liberty wearing the winged cap was symbolic for the freedom of thought.
Also on the obverse is the word "LIBERTY" largely spaced, arcing across the top. A stylized version of the designer's initials appear to the right of Liberty's neck, "IN GOD WE TRUST" appears on the bottom left side of the obverse, and the year appears just below Liberty's collar.
Circling the reverse are the words "UNITED STATES OF AMERICA" along the top, and "ONE DIME" along the bottom. Residing in the center of the reverse is a depiction of the fasces, topped by a battle axe. An olive branch wraps around the back. "E PLURIBUS UNUM" is printed to the right.
Proofs of the Mercury Head dime were last minted in 1942, and the dime's design was retired in 1945.
United States Coinage