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FORVM`s Classical Numismatics Discussion Board  |  Numism  |  Reading For the Advanced Collector  |  Topic: Clashed dies 0 Members and 1 Guest are viewing this topic. « previous next »
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Robert_Brenchley
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« on: November 27, 2007, 11:11:04 am »

Most of us are familiar with brockages, but this is an error which can look like a restruck brockage, but gets far less attention. There's a good page on brockages and clashed dies here: http://dougsmith.ancients.info/brock.html . When two dies are forced together without having a planchet between them, they leave slight impressions on each other. The metal won't be forced up into the die, as it's too resistant, but the outline of the bust, and possibly the inscription, will appear on the reverse. It will be found in incuse on the coin, as the impression on the die will be slightly raised. Doug Smith says he's only seen clashed reverses, but I wonder whether this could be because a reverse often has a larger area of fields, which would show the effect, while the obverse usually has a large bust, which would hide it. if anyone's got a clashed obverse, please post a pic! Logic suggests there snould be as many clashed obverses as reverses out there, after all, unless the two dies were made of different metals, which seems unlikely.
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Robert Brenchley

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« Reply #1 on: December 06, 2007, 05:40:00 am »

Perhaps I should not offer a comment since my study of the matter has not progressed since the page quoted was written but I see on other possible explanation for the clashes being reverses more than obverses.  I am not sure I would rule out the dies being made of different materials but, at least, they were made in different manners since the obverse or anvil die was massive compared to the reverse punches.  Heat treating, whether intentional as part of the manufacture or accidental from rapid use, could make one die softer than the other.  I am no metallurgist and wonder if the question has been addressed by someone who understands the process.  Also, the reverse was the die struck by the hammer so it might be more apt to being deformed compared to the anvil.  To find an obverse clash, I would look for an issue where the obverse was the top die.  There are some Antonine bronzes that I suspect were made with the obverse on the punch but I have so little experience with them that I would not expect to have noted a clash.  We also have to allow for the possibility that some mint authorities may have had different rules for when a die was retired and may have been more tolerant of die damage to reverses than to the portraits.  My page makes it pretty obvious that Severus' Rome tolerated reverse clashes with no problem.  I don't know if the fact that I have seen so many relates to laws of physics, the mint practices or the fact that I have examined 20 times as many Severus/Domna coins as I have any other emperor.  Further, I am at a loss how we are to determine that the lack of obverse clashes is the result of their never having existed or the possibility that they were not tolerated.  Numismatics is a study requiring expertise in history, art and science.  People equally expert (at a high level) in the three are rare.   

My apologies for the horrid photos on that page.  They date from the time I was sensitive to the number of my readers who had dial up access and made more compact images than I would today.  Perhaps I should reshoot and replace but I don't even have access to my pages anymore to upload changes if I made them. 
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« Reply #2 on: December 06, 2007, 06:29:48 am »

I think the reason we see usually see "obverse" die clashes rather than "reverse" ones (I use the scare quotes because it's not really a dichotomy) is because of the typical difference between obverse and reverse designs... An obverse design typically has a large central head, corresponding to a large central depression on the obverse die, surrounded a higher ring where the legends are. A reverse design is typically more intricate and doesn't have such an obvious difference between large raised and depressed areas of the design/die.

I drew a diagram of what's happening with a clashed die in a previous thread:

http://www.forumancientcoins.com/board/index.php?topic=33149.msg212227#msg212227

You can see that the die damage happens when one die sinks into the depressed area of the other die. Due to the typical obverse/reverse design differences just discussed, this typically means the reverse die sinking into the depressed head area of the obverse die, thereby creating a negative impression of that depressed area - i.e. an "obverse" die clash.

I would assume that in the right conditions a "reverse" die clash would indeed be possible, but they are likely very rare because of the rare obverse/reverse paired design characteristics required coupled with the relative rarity of clashed dies in the first place, and the difficulty in always recognising them for what they are. A "reverse" die clash would require a reverse design with a raised (depressed on die) central area that is significantly larger than the bust on the obverse. Maybe some of the laughably small "pinhead" LRBs (caesars) would be a place to start looking!

Ben
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Robert_Brenchley
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« Reply #3 on: December 06, 2007, 03:54:52 pm »

It wouldn't be so obvious on a typical obverse, I agree, and it's pretty clear that the 3rd Century mints at least, were a lot more fussy about the condition of obverses than reverses. We often see fresh obverse dies paired with very worn reverse dies, but rarely the other way round, though it does happen to some extent. They may well have retired damaged obverse dies much faster.
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Robert Brenchley

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« Reply #4 on: December 12, 2007, 06:55:10 pm »

Hello.  I’m new to the Forum, but have been following it for some time as a Guest.  This is my first posting.

Robert Brenchley asks for someone to post a picture of a coin with clashed dies visible on the obverse.  So far no one has posted any pictures. I believe I have such a coin.  It is a denarius with a portrait of the young Severus Alexander, and is catalogued as RIC #5.  I’ve posted two pictures of it.

The first picture shows both sides of the coin.  The clashed dies are visible on the reverse with an up-side-down incuse impression of the bust from the obverse die.  The line going up from Jupiter’s shoulder is the bottom of the chin.  The point of the nose is under the O, with the bridge of the nose and forehead going down to the P.  The top of the head curves around until it meets Jupiter’s left leg mid-calf (on the viewer’s right).

The second picture is a photo of the obverse held obliquely toward the light.  There are four places on the obverse of this coin which, I think, show impressions of the reverse die.  1. There are marks going up from the back of the head toward VRS that are Jupiter’s legs.  2. Above the bow at the back of the head are two marks going up, one of which is curved.  I believe these are impressions of Jupiter’s cloak, where, on his right side (the viewer’s left), part of it curves in toward his knee and part of it hangs down.  3.  In the ribbons behind the head there are several horizontal marks that are Jupiter’s right arm and his thunderbolt.  4.  Around Severus Alexander’s lips is a slight depression possibly made by the top of Jupiter’s scepter.

I’d like to hear the opinions of the other experts here as to whether my analysis is correct.  Thank you.
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curtislclay
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« Reply #5 on: December 12, 2007, 10:35:50 pm »

I think your analysis is undoubtedly correct.  That is a clear case of the rarely observed phenomenon of clashing damage on the obverse die of a Roman coin.

Since the two dies damaged each other simultaneously as they were hammered together without an intervening flan, the relationship between the engraved design and the "clashed" design is of course the same on both sides.  On both sides Jupiter's legs and scepter emerge from exactly the same parts of Sev. Alexander's head, Jupiter's thunderbolt overlaps the emperor's wreath ties in the same way, and so on.

But on re-examination this does not seem to be the case: Jupiter's r. leg is aligned with the back of the emperor's head on the obv., but hits the back of his head at an angle on the reverse.  So apparently the damage on the obv. derives from a different clashing than the damage on the reverse.

I have a denarius of Domitian Caesar and a plaster cast of a denarius of Julia Domna that also show clashing damage on the obv. die. 

It remains mysterious why clashing damage seems so much more frequent on obv. dies than on rev. dies, though as Ben points out clearly the large depression of the portrait on obv. dies cannot be damaged by die clashing.
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Curtis Clay
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« Reply #6 on: December 16, 2007, 02:59:21 pm »

I would like to contribute another example of clashed dies visible on both the obverse and the reverse of this Elagabalus denarius below, although the obverse impression is quite discreet - in the left field there is an impression of grain ears (?) held by Providentia alongside with the cornucopia.  This example seems to support Ben's assumption that the clashed dies effect is less visible on the obverse mostly because of the design differences. Best, Mihail
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Danny S. Jones
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« Reply #7 on: July 14, 2009, 03:46:09 am »

An Example of Obverse Clashed Die 
Septimius Severus AR Denarius INDVLGENTIA AVGG IN CARTH
I posted a picture of this coin on another thread and hope to get other opinions on this coin.
I believe it to be a result of clashed dies. A re-struck brockage is not likely because of the image transfer on both the obverse and reverse. The nose and forelegs of the lion line up perfectly on an image overlay, as well as the bottom of the bust and several of the letters which have been partially obliterated because of the die clash. What appears to be an incuse "V" to the left of the water on the reverse, however, is a mystery to me. It could be the "V" in SEVER"V"S. It is the only part of the dies that do not match up.  The coin seems to be almost in it's original mint state, and an excellent study piece.

In the other thread, CurtisLClay wrote:
Apparently from clashed dies.

On the rev., left of the water, I see an incuse V from the obv. legend.

More interesting still, this may be one of the rare cases where the clashed rev. die managed to inflict damage to the obv. die too, not just vice versa.  Isn't that the snout and front legs of the lion protruding before Septimius' mouth and nose on the obverse?

Can you find other traces of the clash, remembering that clashing produces mirror-image, slightly incuse images of the obv. type on the rev. and the rev. type on the obv.?

Have you seen my thread on the INDVLGENTIA AVGG IN CARTH type under Forvm's Classical Numismatics?

Does anyone else have an opinion on the matter? I'd like to hear from Doug Smith on this coin. Looking forward to replies.

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Robert_Brenchley
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« Reply #8 on: July 14, 2009, 12:19:07 pm »

Most likely clashed dies. I counted up all my Gallic Empire period coins, and found that about 2% were clashed. So it's common enough.
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Robert Brenchley

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« Reply #9 on: July 14, 2009, 03:07:24 pm »

My first inclination is to agree that this is an obverse die clash as described.  It bothers me a bit that the reverse clash is so weak but this could mean that this particular reverse die was relatively hard both protecting itself and damaging the (relatively) soft obverse die.  I am convinced that obverse dies lasted longer because they were prepared in some way different.  This could be being made of a different material, intentionally hardened more or protected by their lower position.  This coin suggests that the last may not be the answer but still allows an individual die being different.  If the dies were all alike, I would expect a lot more reverse damage than we see on this coin before we got any obverse damage.   I agree this is a special coin but I'm not fully certain what it is telling us.

There are a lot of coins of the Severan period with clashed reverses.  As Robert points out, they are common again in Gallic.  It would seem that other periods with fewer clashes did something in a different manner but I have no ide what.  It could be a matter of hardening differently or it could be a matter of policy requiring throwing out damaged dies in some periods but not in those two.  This is a place for more study if someone cares to take it up.


Thanks for the post.  Neat coin!
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