As with all nickels produced since 1866, except for the silver war nickels of 1942-1945, the Liberty Nickels are made out of a composition of 75% copper and 25% nickel. Each coin has a standard weight of 5 grams and diameter of 21.2 mm with a plain edge.
All coins of the series were struck at the Philadelphia Mint until 1912, when coins were also struck at the San Francisco and Denver Mints. The mint mark location appears on the reverse, below the dot between “UNITED” and “CENTS”.
The designer of the Liberty Nickel was Charles E. Barber who had designed many of the contemporary coins of the same era.
Mint Mark: D (Denver), S (San Francisco)
Composition: 75% copper, 25% nickel
Weight: 5 grams
Diameter: 21.2 mm
Designer: Charles E. Barber
taken from: http://libertynickel.net/