1916-D Mercury Dime: How To Authenticate And Identify
1916-D Mercury Dimes are rare so they've become the most faked key date in US Coin history. Often the 1916-S mint mark is altered so it looks like a "D" or the mint mark is engraved or added onto the reverse. It's important to note that many of the altered examples will have wear or damaged to hide the defects of the mint mark.
An important fact you should know is that the D mint mark punch used on the 1916-D Mercury Dime is also the same mint mark used on the 1914-D Lincoln Cent. This fact alone can help you to properly identify an authentic 1916-D Mercury Dime. View the images below for further reference.
As you can see based on the two authenticate images above the mint mark has a definate slant, and almost square appearance with the D's opening has a diamond shape appearance, and with distinct serif tails coming off the back of the mint mark.
In the images above you have the comparison of the 1914-D Lincoln Cent and the 1916-D Merucury Dime mint marks, and they're from the samep punch. However, due to the different locations on each respective coin, and the possiblity of wear or contact marks, circulated examples can have mint marks that appear different but that doesn't mean it's fake.
It's important to notice where the mint mark is located and how it's angled, and the shape, plus only four dies were used for the 1916-D reverse and two of the dies have repunched mint marks, but only two, so this is only a helpful hint if you find an RPM mint mark.
Before you buy what you think is a authentic 1916-D Mercury Dime, make sure you look closely at the images provided and look at certified examples, or buy an example that's already certified by PCGS, NGC or ANACS.
Avoid buying raw examples unless you're 100% positive it's authentic. Furthermore avoid buying possible 1916-D Mercury Dimes from ebay sellers IF they state things like: "I will let you decide if it's authentic." or "Is it an authentic 1916-D?" or "I am not a coin dealer so I will let the bidders decide."
You just can't afford to take a chance and buy a fake or altered key date and if a seller doesn't know the facts then they shouldn't be selling such an expensive coin to begin with and you most certainly shouldn't buy from them.