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Doubled die vs double strike

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I have a few coins that I am honestly not sure if they are doubled dies or doubled stamped. Is there an easy way to tell? It may be my lighting is not great or perhaps it's my eyes. Either way, I would appreciate any advice. 

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Half the battle in identifying a doubled die is understanding the process by which the die is created.  A good read to start off with would be the How Dies Are Made page on John Wexler's site.

To over-simplify it, the die is doubled when the raised image is pressed into the die and it shifts slightly.  That would be like pushing a figuring into forming foam andit shifts or you pull it out and push it in again, but not exactly in the same position.  The image will be in there twice, and at the same level.  S, when you fill it, all of the devices of the image will be the same height, yet somewhat distinct.

The double strike, on the other hand, happens when the die strikes the planchet twice, but not necessarily in the same position for whatever reason.  The first image that was struck into the coin gets squiched down and is not the same level as the second struck image.  When viewing this, the image is what we call "shelf-like" (like looking directly downward at the steps of stairs).  The second image would appear like a shadow or a mirage image does on water.  It is apparent that it is there, but it does not stand out like the rest of the devices.

Taking a look on the internet at images of various known doubled dies may help you to get the feel of what it should look like.  Hope that helps a bit.  And if you are not exactly sure, feel free to post photos and ask!

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Thank you so very much for all of that information. I have researched all of that and I can usually tell the difference but I have a couple of coins that are just plain difficult to tell. I am currently waiting on my new magnifier to ship to me as mine recently fell apart. I tried to post a pic of my most difficult coin here but it keeps telling me the file is too big and it's only 1 picture. I also just came across a 1914 wheat. Normally I know the value of these is generally not high but in the center of the obverse is a deep stamp in it of the number 40. It was very obviously after mint damage. I am wondering if it makes the penny worthless. The rest of the coin is in decent shape. Any thoughts?

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PMD (post mint damage) will not necessarily make your coin worthless, but it is damage nonetheless and will lower the value depending on the type and extent of the damage.  There are some cases, however, (like with trade dollars), where damage (such as "chop marks") can find a niche of collectors that value it for its historical value, so long as it is contained and does not "mutilate" the specimen.

That said, there are those who collect stamped cents as a curiosity, but no real value added.

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On 11/29/2018 at 10:14 AM, SMS said:

Half the battle in identifying a doubled die is understanding the process by which the die is created.  A good read to start off with would be the How Dies Are Made page on John Wexler's site.

To over-simplify it, the die is doubled when the raised image is pressed into the die and it shifts slightly.  That would be like pushing a figuring into forming foam andit shifts or you pull it out and push it in again, but not exactly in the same position.  The image will be in there twice, and at the same level.  S, when you fill it, all of the devices of the image will be the same height, yet somewhat distinct.

The double strike, on the other hand, happens when the die strikes the planchet twice, but not necessarily in the same position for whatever reason.  The first image that was struck into the coin gets squiched down and is not the same level as the second struck image.  When viewing this, the image is what we call "shelf-like" (like looking directly downward at the steps of stairs).  The second image would appear like a shadow or a mirage image does on water.  It is apparent that it is there, but it does not stand out like the rest of the devices.

Taking a look on the internet at images of various known doubled dies may help you to get the feel of what it should look like.  Hope that helps a bit.  And if you are not exactly sure, feel free to post photos and ask!

 

In all my years of collecting, I haven't heard it explained this way. It makes more sense than "a doubled die shows the image rotated slightly around a common center whereas a double strike shows doubling laterally or vertically". That may still be right, but the "same depth" explanation makes sense, too. 

However, it doesn't help when there is significant wear on the coin.

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3 hours ago, thedeadpoint said:

 

However, it doesn't help when there is significant wear on the coin.

It does definitely become much harder when the coin becomes worn.  However, we must remember that normal circulation wear does not remove any metal content from the coin so much as it simply flows the metal (spreads it out).  Thus, a worn coin will have it's devices smoothed out and apparent extra thickness and flatness as the metal spreads.

Without being able to examine a number of MDD coins made from the same dies (or even an exact same coin) at different stages of wear, it is not possible to map the progression of the effects of wear for such coins.  However, knowing the effects of wear on a normal coin's devices, I would think it would become easier to identify MDD in such cases.

I would assume that the MDD would appear more like die deterioration the more wear occurs on the coin until the initial strike on tthe coin is no longer evident.  But, I'm glad that my explanation was able to help in some way.

My 10 year old daughter has become interested in die doubling and I have been finding the need to explain things in a very over-simplified manner to her.  I have found, however, that in a lot of cases, actually seeing examples and comparisons has the largest impact in understanding.

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On 12/4/2018 at 12:08 AM, SMS said:

However, we must remember that normal circulation wear does not remove any metal content from the coin so much as it simply flows the metal (spreads it out).  Thus, a worn coin will have it's devices smoothed out and apparent extra thickness and flatness as the metal spreads.

As a materials engineer and a coin collector, I've never ever heard of that effect and politely point out that it's probably wrong. Can you point me to some literature that shows that?

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On 12/5/2018 at 7:28 PM, thedeadpoint said:

As a materials engineer and a coin collector, I've never ever heard of that effect and politely point out that it's probably wrong. Can you point me to some literature that shows that?

it's become quite a busy end of week here.  Right off the top of my head I can't think of anything in the library to grab for you real quick.  A lot of stuff has been internet interaction over the decades (it's sad how much has literally fallen of the net...not necessarily related to this current topic, but some interesting stuff, nonetheless) so I'm not sure if I'll be able to pull some of it through search that quickly.

But, the gist of it has to deal with the same concept as honing our chef's knives.  The process of sharpening the knife actually removes metal from the blade.  This process, however, is a lot more "crude" compared to the day to day use of the blade.  More pressure, different materials, and the time consumed in the process are different between honing, day to day use, and sharpening.

In day to day use, the knife eventually becomes dull.  During this period, the knife is put under different circumstances in which there are variable amounts of pressure applied, but it is a general rubbing of the the blade against generally softer substances.  Over a period of time, the metal begins to form/bend/flow in the direction of this applied pressure.  Metal itself is not lost...it is simply "squished" thus dulling the blade.

So, we therefore hone the knife.  Applying short periods of light pressure in order to form the metal back into the "sharp" position again (realigning the edges).  As with the day to day use, there is generally no loss of metal involved.  It is when you sharpen the blade that you are intentionally removing metal in order to form a new edge to the blade.

I suggest (as I have also seen others in the past) this is the same with normal "wear" to the metal of the coin.  The metal is being "squished"/formed/flowed/moved....not removed.  It is not until there is damage (whether intentional or not) that we experience the actual removal of the metal.  This can occur through abrasive cleaning, whizzing, , a series of oxidation followed by removal or conservation (as was routinely done in the "good old days"), environmental damage, etc.

Your insight in the matter is greatly appreciated!

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