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If it has any mintmark, it's on the back under the eagle and above the DO in dollar.
Is it a Morgan or Peace dollar? A Morgan dollar features a personification of Liberty with a crown saying "LIBERTY" on it. A Peace dollar has a personification of Liberty with rays of light coming out of her head. The reverse of a Morgan dollar has an Eagle with arrows and an olive branch and a wreath under it. The reverse of a Peace dollar features a perched eagle sitting on a rock inscribed "PEACE". Without knowing the type of coin, it is impossible to state a value.
For U.S. silver dollars, the mintmark is located on the reverse of the coin under the eagle. For Morgan Dollars mintmark's are under the wreath and above the letters DO in DOLLAR. Peace Dollars have mintmark's under the word "ONE" near the eagle's tail.
It's a Trade Dollar not a Morgan dollar. If you look at the back of the coin, the phrase "Trade Dollar" is under the eagle. As to value, take it to a coin dealer for an assessment it may not be genuine. The entire series is known to have had copy's and fakes made.
The coin is a Morgan dollar and assuming no little letters on the back of the coin under the eagle (S-O-CC) the value is $17.00-$26.00
If it has one, it's on the reverse, under the eagle and above DO in the word dollar. If no minmtark the coin was struck in Philadelphia.
All Peace dollars have the same design. The difference between the 1921 Peace Dollar and the 1921 Morgan dollar is that Liberty looks completely different. In the more common 1921 Morgan dollar, Liberty wears a crown with the word "LIBERTY" on it, on the reverse of the Morgan dollar, there is an eagle with olive branches and arrows in its talons along with a wreath under it. On the Peace Dollar, Liberty looks like she has rays coming out of her head and on the reverse there is an Eagle sitting on a rock inscribed "PEACE", there is no wreath on the reverse.
On the reverse side of the coin under the DO in DOLLAR.
It's a PEACE dollar rather than a "peach" dollar, and should have the word PEACE on the back under the eagle. If it doesn't have the word and the eagle's wings are outstretched, you don't have a Peace dollar, you have the more common Morgan design. Please see the Related Questions for more information.
Is it a quarter half or dollar? Sorry looked at this question again. If you mean a dollar coin still need to know if its a Morgan or Peace dollar.
It's a Morgan dollar, the first American eagle was struck in 1986. Check the back of the coin under the eagle to see if it has a mintmark, it can only be an O, S or CC, it may not have a mintmark but it makes a difference in value. There's more information at the Related Question.
Two kinds of silver dollars were made in 1921, a Morgan dollar & Peace dollar. The easy way to tell the difference is on the back of the Peace dollar is the word peace under the eagle so ask a new question when you know what one you have.