It's actually made of copper-nickel, not silver. The mint mark position is the same on all Eisenhower dollars, between the date and the bottom of Ike's image.
No mint mark = Philadelphia
D = Denver
S = San Francisco (collectors' versions only)
By the mint mark on the reverse of the coin, but silver dollar coins with no mint mark are made in Philadelphia
If it has one, it's one the front just above the 7 in the date.
The mint mark on any Morgan dollar is on the reverse above the letters DO in dollar.
No mint mark means the coin was minted in Philadelphia.
The mint mark (if it has one) on all Morgan silver dollars is on the reverse of the coin just above the letters "DO" in dollar.
By the mint mark on the reverse of the coin, but silver dollar coins with no mint mark are made in Philadelphia
The mint mark is under the date, and there is no silver in the coin actually the d is above the year.
No mint mark means it was minted in Philadelphia.
If it has one, it's one the front just above the 7 in the date.
The mint mark on any Morgan dollar is on the reverse above the letters DO in dollar.
If there's no mint mark, then it was minted in Philadelphia.
No mint mark indicates that it was made in Philadelphia.
No mint mark means the coin was minted in Philadelphia.
The mint mark (if it has one) on all Morgan silver dollars is on the reverse of the coin just above the letters "DO" in dollar.
If it has an S mint mark and a whitish color, it's made of copper and silver. If it has a D mint mark above the date or no mint mark (Phila.) it's actually made of copper and nickel. Please see the Related Question for more.
Not always, no. If it was minted in Philadelphia, then there is no mint mark.
above the DO in dollar on the back :]