by Michael Fazarri
Readers will recall that a mintmark is a symbol, letter, or combination of these marks placed on a die to indicate the location of the facility where the coin was produced. Many foreign countries used animals or objects such as an anchor to serve this purpose. Not all coins have a mintmark. For US coins, letters or the absence of them identified the Mint. The micrograph shows an 1839-O half dollar that was struck at the mint in New Orleans.
Coin authenticators spend much of their time examining mint marks which are an important area to study both technically and historically. Early authenticators combined the two words into one and then shortened it to “MMK.” Thus, a genuine coin with an added mintmark was recorded as having an “AMMK.” Go figure, but that’s the way we did it in the old days.
All coinage dies for U.S. Branch Mints were prepared in the die making shop at the Philadelphia Mint. For this reason, the mintmarks on coins will generally be of the same shape and size (style) over a certain period of time because the same letter punch was used. Thus, similar style mintmarks overlap the dates which include many of the “key” coins in a series such as the 1909-S VDB cent, 1916-D dime, and 1896-S quarter. We should all be thankful this is the case.
For example, we can seek out a less expensive coin like a 1910-S cent to learn the mintmark style of several coins of that era – even the 1915-S Pan Pac slug! Otherwise, the mintmark differences found on common coins like an 1881-S Morgan dollar are only important to specialists. On occasion, a significantly different mintmark was used in error or out of necessity creating a break in this regularity of a coin series. Some of these varieties such as the 1905-O dime with a very small mintmark are eagerly sought.
The position of a mintmark may be different on two otherwise identical coins because originally, they were placed into each die by hand. Thus, while the style may be identical, their location will vary according to the number of dies used to strike coins of that date. Unfortunately, it is not possible for the human eye to see some of the minuscule differences in position even when using a microscope. Collectors of today can find images of the various mintmarks and their position on “key” date coins on the Internet.
As a rookie authenticator in the 1970’s, I was fortunate to be taken into the Engraving Department at the Philadelphia Mint on two occasions. One time, I stood next to a cart of Washington quarter dies as an engraver wearing a magnifier was applying mintmarks to them. He reached over to get a die and placed it in a fixture on his desktop. Then he took a small hammer and showed me the punch with the tiny letter at one end. When I handed it back, he looked to make sure it was right side up and placed it on the die guided only by his experience as to its correct position. He gave the punch a light tap with the hammer and then examined the small indentation it had made into the die. Satisfied with the position, he placed the punch against the die again until he felt it mate with the original indentation. Then he gave the punch another blow.
To this day, I’ve wondered how much of this operation was a “show” for his two guests watching with the Chief Engraver. If I had a cart with two racks of dies and a lunch break in thirty minutes, I wonder if I would have been so meticulous about the mintmark’s position or its depth into the die. Perhaps, grab a die, smack the punch, grab a die…smack the punch was found to be unproductive. We often joked about what the engravers were thinking when they produced D/Horizontal D, or upside-down mintmarks on coins. These are the same folks who gave us interesting coins with the date numerals being a part of the design of some coins.
There are several ways to alter a coin by adding a mintmark. Usually, they can be detected because the surface around the letter is no longer original, the mintmark is not perfectly joined to the field (leaving a tiny seam), or the style of the mintmark is incorrect. One of the most devious and totally unexpected at the time alteration methods involved drilling a hole into the edge of the coin so the fake mintmark could be embossed on the coin from below! When the hole was filled and the edge was “fixed,” it was an alteration you had to be looking for in order to detect it.
Your first defense against buying a coin altered in this way is knowing the style of the mintmarks on the coins you collect. Your second defense is to send any pieces that are suspect to a major authentication service.