It's the designers initial. If it was a mintmark it would stand for West Point. The West Point mint didn't make any such coins.
Please check your coins date again as there were no Mercury dimes made until 1916 and the "W" you are seeing is the designers initials AW which appears as a "W" at a casual glance.
The mint mark position on all Mercury dimes is to the right of the E in the word ONE on the reverse of the coin. (The "W" on the front of the coin is the designer's initial.) No mint mark = Philadelphia D = Denver S = San Francisco There's more information at the Related Question.
1937 Mercury Dimes were minted at Philadelphia (dimes which have no mint mark), at Denver (dimes which have a D mint mark), at San Francisco (dimes which have a S mint mark). There is no W mint mark on a dime in 1937.MintmarkThe "W" you see on the front of the coin is actually a combined "AW" monogram for the coin's designer, Adolph Weinman. This monogram appears on all Mercury dimes, regardless of where they were minted. Mintmark ContinuedThe mint mark would be located on the reverse side of the dimeLook for the phrase at the bottome " ONE DIME"The mark should be after ONE
Mercury head dimes from 1940 to 1945 with or without mintmarks are all very common, especially in circulated grades. Most are valued just for the silver, as of today 10-13-11 it's $2.00. An uncirculated coin is $3.00-$4.00.
It's not that simple. It depends on the coin's date and condition. Sometimes Mercury dimes from Denver are the most valuable, sometimes San Francisco. See the link page below for prices by mint mark and condition.
The mint mark position on all Mercury dimes is to the right of the E in the word ONE on the reverse of the coin. No mint mark = Philadelphia D = Denver S = San Francisco
The mint mark position on all Mercury dimes is to the right of the E in the word ONE on the reverse of the coin. No mint mark = Philadelphia D = Denver S = San Francisco
Value is about $1.00 and JS is NOT a mint mark it's the designers initials, the mint mark is on the reverse. Obverse mint marks were not used on dimes until 1968
W is the designer's initial (A. A. Weinman) The West Point Mint opened in the 1980s.The mint mark position on all Mercury dimes is on the back, next to the E in ONE. Check the Related Question for more information.
Liberty dime could refer to either the Barber or Mercury dime. The mint mark on Barber dimes is located on the reverse (tails) side, right at the bottom. For Mercury dimes, it's also located on the reverse side, near the bottom, just to the right of the word "one."
The Mintmark is on the reverse to the right of the "E" in ONE near the rim. It's in the same place on all years of Mercury dimes.
The mint mark position on all "Mercury" dimes is next to the E in ONE on the back. No mint mark = Philadelphia S = San Francisco D = Denver