2008-D LMC Improper Annealing?

I'd like to know if there's any value with this improper plating issue?


Below are some examples of coins I experimented with to try and replicate what the first 2 responders said it was.

First is one done through heat transfer. I stood a bolt on end and placed the penny on top. Then heated the base of the bolt until I saw the slightest color change. The damage you see happened during the cooling process.




Next penny I created by holding it above a Bic lighter with the flame about .25" away from the center of the cent. I stopped as soon as I noticed the copper plating vanish. As seen here, the coin has changed to a more golden hue and the plating vanished from the field quicker than the relief. Where it's thicker. Hard to tell in the pics but there is slight pink-violet "toning" to the area of exposed zinc and copper plating.




Third up is one I used a Hobbyist torch. This one was held away in the same fashion as the Bic lighter. Here you can see again, most of the removed copper plating took place in the field rather than centered over Lincoln, where the flame was concentrated. You can also see some of the copper plating removed from the reverse as well as the whole coin is discolored.




Lastly, this one was torched as well with the hobbyist torch. This time held with the flame kissing the coin for a second until the slightest color change. This time we got a little bit more centralized copper removal over the relief. However there is still major discoloration/"toning" to the entire coin and between the pillars on the reverse.




And all of them together on the reverse to show the color change throughout all of them. The far left is an untouched run of the mill Lincoln Cent.

Silviosi, thank you for your response. What does "Cu" stand for?
And what coin are you referring to when you say the heat came from the bottom up? How would you go about recreating what is displayed in the first post? There is no progression color transformation on the original coin posted and zero discoloration on the reverse. Which I think would be impossible if there was a heat source on that side. Color transformation from heat will go from copper (original plating) - yellow - zinc with pinkish hue at the edges of the yellow and zinc. Something the original coin shows no sign of. No matter what angle it's viewed from.

What other forms of heat should I experiment with? Electricity? A slower lower heat from heat transfer? Should I lay it on top of my wall heater for a week? Maybe a heat gun? Would it be possible to get a heat gun hot enough to remove the copper plating? Even if it would be, I would think I would need to concentrate the airflow with something like a funneled tip. Otherwise the flow would be to broad and encompass the entire coin.

Just trying to wrap my brain around the whole "it was caused by heat" stigma. Because if that were the case. We should be able to find a way to recreate it. I'm willing to try just about anything within my abilities.

I am surprised the coin did not just melt away using anything other a bic lighter. I remember when the zinc cents first came out, I used a plumbers propane torch and the coin vaporized away.
John1

Which, to me at least, would be impossible without the copper layer showing signs of discoloration from being heated.

@silviosi, I do not appreciate the derogatory statements toward Californian nor my level of intellect. If I do not understand something, then isn't that the perfect opportunity to dive in and learn? The whole point in me joining this community is to LEARN. The difficult part I'm having is the language barrier we have. No to offend you, but I have to read your statements over and over to make sure I'm understanding you.

I'm still unsure if you think this was caused pre or post minting.

I'm not trying to prove that I am right. I am just a curious soul. It was suggested that applied heat caused this issue post minting. If that is the case. How might one suggest it was done? I tried a few different ways from the aforementioned above.

I can try copper plating a coin to see for myself how it concentrates in the center first. But aren't the metal sheets plated before the blanks are punched? So plating a coin wouldn't be the same. If I do try plating a coin. How would you recommend I suspend the coin in the copper sulfate solution without the hardware effecting the plating? Alligator clips would leave uneven copper plating where it's secured to the coin. Could I set the coin on the bottom of the glass beaker? Would the side on the glass get coated? I will look into this later.

Thank you for the suggestion on the coin show. Maybe I can get the time to make it there.

This are some of the ones I found in string rolls.

@ Cu : the color is a normal Zn who come back to his normal stage.
@ PETE: Normal the blanks is suppose to be clean after blanking?!!!? I like your hypotheses.

Me I supposes some could be from the Heats of the Dies. In time I present to the Mint the Document about over heat of the Dies and the danger for the production quality, but as the Mint is do not come back to you.

@Numismax: Far from me to offend you, but to go more far will be complicate. I speak scientific dialect and not the common language, I teaches in DC Mc Hill, in Corpus Christy in Montreal McGill but science. I had residents from over the word and no problems till here sometimes some persons do not accept my way to show what is my opinion and them to analyze what it is..

Is very good to be curious and try to learn and here it is the place for the coins not the forensic of the coins.


PS: The electroplating of the blanks do not use copper sulphate

Excellent DATA. You nail all the suppositions here. PM me to has an interesting Doc for an DATA Dragon.