Liberty nickels were only struck at Philadelphia from 1883 to 1911, so they do not carry a mint mark. 1912 nickels may have a D or S under the dot at roughly the 8:00 position on the reverse side.
Buffalo nickels have their mint mark on the reverse under the words FIVE CENTS.
On a 1904 nickel, the mintmark can be found on the reverse side of the coin below the Roman numeral V representing the denomination of 5 cents. If there is a mintmark, it will be located near the bottom of the coin just above the rim.
Look at the coin again, no Liberty Head nickel had a mintmark until 1912.
There were about 10,041,000 British 1904 Sovereigns minted at the Royal Mint London (no mintmark). There were about 3,743,000 British 1904 Sovereigns minted at the Melbourne Mint (mintmark = M to the right of the date). There were about 4,506,000 British 1904 Sovereigns minted at the Perth Mint (mintmark = P to the right of the date). There were about 2,986,000 British 1904 Sovereigns minted at the Sydney Mint (mintmark = S to the right of the date).
It depends, as there was actually a change in composition In late 1942.-- If the nickel has no mintmark, or a small mintmark to the right of Monticello on the back of the coin, it is 75% copper and 25% nickel.-- If the nickel has a large mintmark above the dome of Monticello on the back of the coin, it is 56% copper, 35% silver and 9% manganese.
The last Buffalo nickel was made in 1938. A 1942 dated Jefferson that has a large mintmark on the reverse is 35% silver and worth about $1.00. If it does not have the large mintmark just spend it.
Any Buffalo nickel with no mintmark was struck in Philadelphia. Nickels did not have a "P" mintmark until 1980.
The last Buffalo nickel was made in 1938. A 1942 dated Jefferson that has a large mintmark on the reverse is 35% silver and worth about $1.00. If it does not have the large mintmark just spend it.
The "P" is the mintmark of the Philadelphia Mint. All U.S. coins from 1980 to 2012 made at this mint have a "P" mintmark. It's just a nickel, spend it.
For the type I the mintmark is filled and the type II the mintmark is clear.
6-18-11>>> The coin is a common date Liberty Head nickel, coins in average circulated condition have values of $1.00-$3.00.
If it has one it's on the reverse under FIVE CENTS
Six cents to $1, depending on mintmark and condition.
The "F" under the date of the buffalo nickel isn't a mintmark, it's the initial of the coin's designer, James E. Fraser. The mintmark position is on the back under the words FIVE CENTS. Please see the question "What is the value of a 1927 US nickel?" for more information.