Very often we hear from a new collector who will discover a Roosevelt dime in their change and after some googling they will ask if it’s worth thousands of dollars.
The reason this is so confusing to the novice holding a “no S” dime in their hand is due to a lack of knowledge about two things; proof coins and a bit of United States mint mark history.
I’ve put this information together in order to help educate and hopefully answer anyone who might be asking this question.
There are 4 specific years in which rare “no S” dimes were minted. Those years are 1968, 1970, 1975 and 1983. In each case, without exception, these rare coins are *PROOF* coins which were minted in San Francisco. When the dies used for minting these coins were prepared, they somehow did not receive an S mint mark. Understanding what a proof coin from San Francisco is will help you determine if the “no S” dime you have is one of these rare coins.
How to determine if your dime is a proof dime
Not all coins are minted for use as money. In addition to the coins in your change (aka business strike coins), the U.S. Mint also produces proof coins which are typically ONLY for collecting. It’s also, important to understand that proof dimes for these years were struck at San Francisco, whereas the business strike dimes were struck in Philadelphia and Denver. This is typical for all of our coins today.
The differences between a proof dime and a business strike dime found in change, can typically be seen by comparing the two side by side. It’s important to know what those differences are so you know what you’re looking for. Proof coins appear very different from business strike coins, because the minting process is completely different. The four differences, explained below, should be enough to help you determine if the coin you found is a proof dime or just a regular business strike coin.
On a “no S” proof dime the fields will be deeply mirrored. They are flashy and you can see reflections of what is directly in front of the coin when you are looking at it. It’s like looking into a mirror. To me, they have the look and feel of liquid metal. The below pictures hopefully demonstrate this mirrored effect of a proof dime’s obverse field.
Notice in the above pictured proofs how each dime’s field is highly polished and shiny. You can tell as you transition from the rim of the coin to the center that the field is very smooth and looks like a concaved mirror.
Now, for comparison’s sake, below are two examples of mint state, business strike dimes minted in Philadelphia. Notice here, how the fields do not exhibit the mirroring. Rather, the fields on both seem to have a creamy or frosty finish, like a mirror which has been fogged over. The fields on these coins also show metal flow lines, and when compared to a proof the fields seem blurry or diffused. They don’t seem highly polished, yet they have a shine to them. Also note that neither one of them have an S mint mark; this will be discussed in detail later.
This difference in the field appearances is the first thing that will clue you into your dime being a proof or not. Are the fields of your “no S” dime deeply mirrored like the first two dimes, or are they frosty or blurred like the second two dimes?
The Rims: Another key visual indicator between a business strike dime and a proof dime is the rim of the coin. Again using the above pictures, notice on the proof dime how the rims of the coin are thicker and are more squared off when compared to the business strike coins. The proof rims, visually, have more definition to them. On the business strike coins, the rims are thinner and less squared off.
The Definition of Devices: The devices of a coin are all the pieces which make up the design of the coin. Roosevelt’s bust, the date, the mint mark, the motto, etc. As you observe the proof dime and then contrast its appearance with the business strike dime you should be able to see that all the devices on the proof are more sharply struck. They stand out in the fields more than they do on the business strike dimes. While the devices are clearly seen on both coins, the proof’s devices pop more, they look like they were pressed into the coin more so than the business strike dime.
After reading this information you should now be able to tell if the dime you have is a proof or a regular business strike dime. Remember the rare “no S” dimes are all proofs.
Even after understanding the difference between a proof dime and a regular dime, the next question most have about their “no S” dime is why they have a dime with no mint mark form the same year that these rare “no S” dimes are found. This question comes from the fact that since 1979 the Philadelphia mint has put a P mint mark on all coins minted there, except for the Lincoln cent. So most newcomers to coin collecting are used to seeing their change with either a P, D and in some case an S mint mark. What’s not typically known, however, is that up until 1979, NO coins minted in Philadelphia received a mint mark, with the exception of a brief 3 year period (1942-1945), when the Philadelphia mint did place a P on the Jefferson nickels minted in Philadelphia. This was discontinued, however, in 1945 after WWII. This means that for each of the three years in which rare “no S” proof dimes are known, 1968, 1970 and 1975, there were proof dimes from San Francisco which had an S mint mark and there were also dimes minted in Philadelphia which didn’t have a mint mark at all.
It is the combination of being a proof dime from San Francisco, and not having that S mint mark that makes the “no S” proof dimes so rare. A business strike dime (just a regular dime) minted in the same year at the Philadelphia mint will also not have a mint mark but it will only be worth face value if found in pocket change and a little more than face if it’s found in uncirculated condition.
More References for “No S” proof Roosevelt dimes: