Bottom line: You’ll see that on the 1918-D Mercury Dime, there’s a small mint mark D after the “ONE” in “ONE DIME.” Otherwise, the 1918-D Mercury Dime is almost identical to the 1916-D ...

a missing “S” mint mark, which made the coin a valuable collector’s item. On October 27, three sisters from Ohio, who owned the dime jointly, sold it through GreatCollections, an auction ...