Another die variety has come onto the scene recently. Like the Repunched Mint Mark (RPM) varieties, the Over Mint Mark (OMM) varieties, and the Dual Mint Mark (DMM) varieties, it is the result of the mint mark being hand-punched into the working dies. The culprit so far has been the S mint mark.
Inverted Mint Mark (IMM) varieties resulted when a mint mark was punched into a working die in an inverted or “upside down” position from the intended position of the mint mark. For some mint marks it was fairly easy to tell in the mint mark punch was in a proper orientation. These would include the D mint mark, the C mint mark, the CC mint mark, and the P mint mark. Examples of inverted D mint marks are known, but in all cases they were repunched with a D in the proper orientation creating D over Inverted D RPM varieties. Some examples of these can be found on the RPM and OMM Varieties page of this website.
The main culprit so far for the Inverted Mint Mark variety has been the S mint mark. Over the years the Mint has used a number of different styles of S mint mark on the various denominations of U.S. coins. It would seem at first glance that there shouldn’t be any difference between an S and an inverted S, but that isn’t the case. The styles of S mint mark were not designed with symmetry in mind. There are distinct differences between the top of the S mint mark and the bottom of the S mint mark on most styles of S that the Mint used. As a result, if any of these S mint mark styles were punched into the working die in an inverted (upside down) position, you should be able to see the difference.
For some years, especially in the mid-1940’s, as many as three different style S mint marks were used on a given denomination in a single year. For example, the 1946-S Lincoln cents can be found with three different styles of mint mark. They are referred to as the “Ball Serif S” style, the “Sans Serif S” style, and the “Trumpet Tail S” style.
This is the "Ball Serif S" mint mark used on the 1946-S Lincoln cents. Note the rounded serif at the top of the mint mark and the flattened serif on the bottom of the mint mark.
This mint mark style seen on a 1946-S Lincoln cent has come to be known as the "Sans Serif S" mint mark. There is no serif at the top of the mint mark while the bottom end of the mint mark is flattened.
The "Trumpet Tailed S" mint mark, which can also be found on the 1946-S Lincoln cents, has a lower mint mark that resembles the front end of a trumpet and a normal serif at the top of the mint mark.
While these different styles within the same year make for an interesting collection in and of themselves, you will notice that each of the S mint mark styles illustrated is not symmetrical. There are distinct differences between the top of the mint mark and the bottom of the mint mark, so if any of these were punched into the die in an inverted orientation, you should be able to see the difference and some collectors have been noticing.
More and more examples of Inverted Mint Mark (IMM) varieties for S mint coins are being found as collectors become aware of their existence and start looking for them. We recently had the opportunity to photograph a specimen of an inverted mint mark variety for the Ball Serif Style S on the 1946-S Lincoln cents.
This again is the "Ball Serif S" mint mark punched in a normal orientation on a 1946-S Lincoln cent.
This is a 1946-S Lincoln cent with a "Ball Serif S" mint mark punched in the inverted position. Hopefully you can see the difference between the two.
In looking through my own collection of Washington Quarter doubled dies for a book project I was surprised to find two different 1945-S quarters with reverse doubled dies on which one of them also has an inverted mint mark. Both of the 1945-S doubled die quarters have the Trumpet Tail S style of mint mark. On the doubled die listed as 1945-S 25¢ WDDR-002 it is in the normal orientation, but on the doubled die listed as 1945-S 25¢ WDDR-003 it is definitely inverted.
This "Trumpet Tailed S" which is punched in the normal orientation can be found on the reverse of a 1945-S Washington Quarter doubled die variety that we have listed as 1945-S 25¢ WDDR-002. Note the doubling on the left branch and on the upper right side of the R in QUARTER.
This inverted "Trumpet Tailed S" mint mark can be found on the 1945-S Washington Quarter doubled die reverse that we have listed as 1945-S 25¢ WDDR-003. The S mint mark also shows some mechanical doubling, but close inspection shows that it is clearly an inverted mint mark. Again note the nice doubling on the left branch.
The key to success in finding Inverted Mint Mark varieties is knowing what the "normal" mint marks are supposed to look like for any given date and denomination. Once you know what "normal" looks like, you will have an easier time spotting the inverted mint marks.
All Inverted Mint Mark (IMM) attributions for the Wexler Die Variety Files are done by NCADD President John Bordner. Questions about these die variety types should be directed to Mr. Bordner.
If you have coins that you suspect are Inverted Mint Mark varieties and would like to find out if they are indeed genuine IMMs, or if you know they are genuine IMMs and would like to find out if they are listed in the Wexler Die Variety Files, you can send them to Mr. Bordner for attribution. If you are sending coins to him, the following guidelines must be followed.
1. The fee for attributions is $3 per coin. Return postage and insurance is extra and must be included with any coins sent.
2. You may send up to, but no more than 5 coins per shipment. If packages are sent with more than 5 coins, it will greatly delay their return. Five coins will be processed and the package then placed at the end of the mail line until it comes up again.
3. Do NOT send any additional shipments until the previous shipment has been returned.
4. NEVER send coins by Certified Mail. If they are lost or stolen in the mail you will NOT be able to recover any of their value. Certified Mail does NOT carry any insurance. All coins should be sent by Insured First Class Mail or by Registered Mail. By far, the safest way that anyone can send coins is by Registered Mail. It is more expensive but it is the safest way to send them as the package must be signed for by every individual that touches it along the way. If coins are sent by Insured First Class Mail but an actual value can not be determined because the coins have not yet been attributed as varieties, you will not be able to collect any insurance on them beyond face value, or what you paid for the coins if you have a receipt.
5. If you would like to receive a notice that the coins arrived here safely, you can take advantage of the delivery confirmation services available through the Post Office, and also the return receipt services available from the Post Office.
6. Make sure that you package your coins very carefully. If they can move about in the package, they might be able to tear out of the package and become lost. I recommend shipping in a padded mailer available from the post office, Wal-Mart, Staples, etc.
7. Please send your coins in plastic or vinyl flips from which they can easily be removed. Do not send the coins in 2x2’s that have been stapled.
8. We do NOT attribute foreign coin varieties – only varieties on U.S. coinage.
9. Once the coins arrive they will be processed as quickly as possible. Due to large demands on the attributers, it may take anywhere from 4 to 6 weeks before the coins are processed and returned. It is usually less than that but we do ask your patience once they are sent.