Considering Mint-State 60 Grade or lower = The 1893 with the "S" mintmark. Values range from $6500 for heavily worn to $90,000 for a specimen in MS-60 range. A 1895 with the "O" mintmark bearing the Grade MS-67 was sold at auction for $575,000 in November, 2005 - but that was an exceptional unique grade for that piece.
It really depends on the year, but in general no mintmark is very common (for the Philadelphia mint) as is O for the New Orleans mint, while S for the San Fransisco mint is common for most but scarce for some, and the most valuable mintmark in general is CC for Carson City.
The 1882 Morgan dollars are common date coins. They were struck at the Philadelphia, Carson-City and New Orleans Mints. In terms of number of coins made, the Carson-City issues are the lowest mintage. The New Orleans issues have a overmintmark error of O/S, this is the only coin some would call rare.
In terms of the number made, that would be the 1895 Morgan silver dollar minted in Philadelphia, Pennsylvania. Only 12,880 were struck.
No such thing as a "strike mark" but U.S. coins do have Mintmarks. For Morgan dollars, they are on the reverse just above the DO in DOLLAR.
The mint mark on any Morgan dollar is on the reverse above the letters DO in dollar.
If it has one, it's on the reverse above the 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.
Not always, no. If it was minted in Philadelphia, then there is no mint mark.
The mint mark on any Morgan dollar is located on the reverse (tails) side, near the bottom, just above the letters "do" in the word "dollar."
If it has one, it's on the reverse above DO in the word dollar.
If it doesn't have a mint mark, that means it was made in Philadelphia.
The mint mark on a Morgan dollar (if any) will be found on the reverse of the coin under the wreath between the "D" and "O" in "DOLLAR".
The mint mark on Morgan silver dollars can be found on the reverse (tails) side, near the bottom, just above the letters "do" in the word "dollar."
The mint mark on all Morgan silver dollars is located on the reverse side of the coin just above the letters "DO" in the word "DOLLAR".
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.