The mint mark on Morgan dollars is on the reverse (tails) side, near the bottom, just above the letters "do" in the word "dollar." If nothing's there, it means your coin was minted in Philadelphia.
If you know it's a 1921 "S" Morgan you found the mint mark
No, there is no known 1882 Morgan dollar with a double mint mark. Morgan dollars were produced at different mints, and while there are various mint marks (such as S for San Francisco and CC for Carson City), a double mint mark is not a recognized variation for this coin. Any claims of such a coin would likely be due to a misinterpretation or counterfeit.
Please check again and post a new question. The C mint mark was only used on gold coins minted from 1838 to 1861. Your coin should either have no mint mark, a D, or an S.
For coins dated 1906 to the present, it means the coin was made at the Denver Mint. A "D" mint mark on an old (1838-1861) gold coin means it was made at the long-closed gold coin mint at Dahlonega, GA.
To determine where a coin was minted it is necessary to locate the mint mark. This mark is a small letter or letters located somewhere on the coin. For the Morgan Dollar, this mark is located on the reverse [tails] side of the coin just above the letters "DO" in the word "DOLLAR". For the Carson City mint the mark is a "CC". {quotes are mine}
The mint mark (if it has one) on all Morgan (1878-1904 & 1921) silver dollars is on the reverse of the coin, just above the letters "DO" in dollar.
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.
Sorry no Carson City mint marks in 1887 on a Morgan dollar. Look at the coin again.
According to coinbrag.com the mint mark is located on the obverse over the date.
mint mark is to the left of the value on the reverse.
$680 to $27,500 depending upon the mint mark and the condition of the coin.
The mint mark on a $5 gold coin from that era is on the reverse (tails) side, just below the eagle.