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 Replies: 14 / Views: 909 |
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Pillar of the Community
United States
3281 Posts |
I have no clue as to what this is. At first look, it seems to be a stain, but after inspection and looking at it from multiple angles with my actual eyes, it seems as if there is a winding crack through the plating of the coin. Any idea as to what this is? Is it damage, or something else?    |
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Moderator
 United States
96451 Posts |
If you saying that the plating was cracked, I think I would see some Zinc showing under that anomaly
Maybe a die issue?
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Pillar of the Community
 United States
3281 Posts |
Look at the last photo Dearborn, the zinc core is visible. The gray color is the zinc.
Perhaps, I'm thinking it might be a plating issue but your guess is as good as mine.
Edited by SilverCents
06/25/2021 6:00 pm
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Bedrock of the Community
United States
62064 Posts |
No a premium and a death warrant for the coin. It will continue the count down until it is going to disappear years on down the line.
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Pillar of the Community
United States
3281 Posts |
Thanks Coop! I suppose the conclusion is that this coin has been damaged by outside sources? Meaning because it's PMD, I should just throw it out? |
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Pillar of the Community
Canada
6244 Posts |
It is not a PMD on the meaning. We can say like this because the collectivity adopted this term. I find this effect on plated coins by hazard. Tomorrow Saturday I will explain more, but for the moment I answer: it is a failure of the cleaning planchet combinate with the after strike environment conditions. |
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Pillar of the Community
United States
3281 Posts |
Ah gotcha I think I understand. There was an issue with the planchet, or the plating, which in turn overtime cause the plating to peel back, and it will continue to until the entirety of the plating is removed.
I am looking forward to the in-depth explanation. Thank you very much!
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Pillar of the Community
Canada
6244 Posts |
@Silver. Like I promise to day I will tell you what I find out by hazard.
I have 'it on my car's coffee cup Us and CAD plated penny. Was there for months and months. Every day a warm good Brazilian or Columbian coffee cup. After a while I collected from and wash with my Borax solution and see that some of them has the plating crack. I knows that at the moment when I put there the surfaces of the coins was correct. So I took the coins in my Lab and peel those cracks, took from under cracks samples and the analyze with the amorph material spectrum. The result was a surprise: Was correct to find some zinc or steel oxide (depending of the coin) but common to all (around 6 coins from 20 - 25 in the holder) has Sodium. In the mint process the only place the Sodium is present it is only on the wash of the plate after milling, before plating.
So my conclusion was some residue of the wash left and contain Sodium.
I repeated the experience with full roll of US penny first and then from 50 coins from Canada. US: 4 coins show something after 3 month. The Canadians coins was worst 11 from 50 coins. My conclusion and also of my partners was Sodium residue and because is expose to the slow temporary changes of the temperature, the sodium will form crystals which will broke the tinny plating coat. This crack of the plating could be anywhere on the coins and has no link of the forms with de-lamination.
Me I do not keep the coins because I do not thing it is a numismatic interest due to the fact it is an environment interference.
Hope at your convenience my funny lost of the 10 hours of Lab work but a new knowledge.
Silvio
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Pillar of the Community
United States
3281 Posts |
Wow, you really did do an in depth experiment to figure out what caused such an effect.
I thank you greatly for giving me this knowledge! You are indeed a true chemist.
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Pillar of the Community
Canada
6244 Posts |
@Silver, Thanks, I am not a chemist, I am an Ph Dr in radio-oncology obstetric gynecologist at his retirement. Also with a master in molecular science. I like the chalenge of the mint process and a collector from age of 3 (first collection is funny: BEANS seeds!!! HeHeHe!)
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Pillar of the Community
United States
3281 Posts |
Ah I see, I meant it as a joke really. I wasn't assuming you had a PhD in Chemistry, I just thought that your mind was in the right place to think like a chemist. A radio-oncology obstetric gynecologist, my goodness, that is quite the title! Well, I once again thank you very much for your help. You are quite the individual, very impressive background!
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Pillar of the Community
Canada
6244 Posts |
Thank you for your very kind and sweet words. In fact is me and the community to thanks you posting yours's find and discovery. Hope majority will appreciate and the jalousie will stand off.
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Pillar of the Community
United States
3281 Posts |
 Thank you very much, and same to you! |
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Pillar of the Community
United States
5775 Posts |
Silviosi, thank you for the experiment also. I love the tenacity and depth with which you tackled this for the community. And I like your first collection. Seeds!!  Words of encouragement are one of the major food groups.
We need to consume them regularly to thrive and grow.
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Pillar of the Community
Canada
6244 Posts |
Thank you Pete, I really appreciate. I try my best.
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Replies: 14 / Views: 909 |
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Posted 06/25/2021 12:41 pm
