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1983 Lincoln Cent – Defective Bronze Planchet. NGC VS PCGS.

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  • coinbufcoinbuf Posts: 12,445 ✭✭✭✭✭

    @ambro51 said:
    PMD

    Fair enough, the rev looks especially off and the mushy poorly defined details are suspicious and could support the post mint replating suggestion.

    My Lincoln Registry
    My Collection of Old Holders

    Never a slave to one plastic brand will I ever be.
  • JBKJBK Posts: 17,423 ✭✭✭✭✭

    The label will apparently read "Mint Error" with the heavy plating mentioned as the error.

    I assume if it was PMP (post mint plating) then it would have been body bagged or listed as "damage" with the plating mentioned.

  • CaptHenwayCaptHenway Posts: 33,816 ✭✭✭✭✭

    @JBK said:
    The label will apparently read "Mint Error" with the heavy plating mentioned as the error.

    I assume if it was PMP (post mint plating) then it would have been body bagged or listed as "damage" with the plating mentioned.

    If, hypothetically, they missed the plating.

    Numismatist. 54 year member ANA. Former ANA Senior Authenticator. Winner of four ANA Heath Literary Awards; three Wayte and Olga Raymond Literary Awards; Numismatist of the Year Award 2009, and ANA Lifetime Achievement Award 2020. Also won the PNG's Robert Friedberg Award for "The Enigmatic Lincoln Cents of 1922," Available now from Whitman or Amazon.
  • CoinOMCoinOM Posts: 72 ✭✭

    I would have XRF tomorrow. I hope it will give some more answers.

  • MsMorrisineMsMorrisine Posts: 39,370 ✭✭✭✭✭

    i would think it will be majority copper if the plating is so thick

    Current maintainer of Stone's Master List of Favorite Websites // My BST transactions
  • MsMorrisineMsMorrisine Posts: 39,370 ✭✭✭✭✭

    the thing that needs to be done is a specific gravity test

    Current maintainer of Stone's Master List of Favorite Websites // My BST transactions
  • Mr Lindy Mr Lindy Posts: 1,678 ✭✭✭✭✭

    I appreciate how much sharing you have been with your journey. I have seen posts elsewhere too, so education provided elsewhere has enlightened others.

    For me I have learned that with zinc dies struck on copper blanks I will now require SG results on slab. Over years I have seen "SG" number on slab a couple times. Earlier in this thread a $250 pcgs fee would have achieved your CRITICAL missing data point. You've saved me thousands & now I am confident how I will proceed in future with other similar offers. This can be $5k plus items in nice mint state that I passed on. Since 1982 I've seen maybe 8 of these for sale.

    I do not buy damaged coins so yours with goofy reverse was always a no go from the get go. And weight spec is goofy too.

    Happy Tuesday !

  • MsMorrisineMsMorrisine Posts: 39,370 ✭✭✭✭✭

    @Mr Lindy said:
    Over years I have seen "SG" number on slab a couple times.

    certainly there was more on the slab. do you remember the text?

    Current maintainer of Stone's Master List of Favorite Websites // My BST transactions
  • coinbufcoinbuf Posts: 12,445 ✭✭✭✭✭
    edited June 16, 2026 5:39PM

    @CoinOM said:
    I would have XRF tomorrow. I hope it will give some more answers.

    Nope it will not. All that will do is spark your hopes and have you chasing down the rabbit hole again. Face it, you have a mint error just not the one you want it to be.

    My Lincoln Registry
    My Collection of Old Holders

    Never a slave to one plastic brand will I ever be.
  • Mr Lindy Mr Lindy Posts: 1,678 ✭✭✭✭✭

    First time I saw SG including a number it confused me & I moved on. Second time I recalled 1st time seeing odd detail prior, but did not buy it either. Now I feel I have a handle on it as its a pcgs $250 service. Now I think I get it & understand it. I like errors I can recognize with my eyes. Copper struck by zinc dies have always been hard to visually verify 100% and they are pricey. Never owned one and for 5K plus likely never will. I remain hesitant so I stick with what feels right and I own several 5k plus error goodies. All are items I feel confident archiving.

    @MsMorrisine said:

    @Mr Lindy said:
    Over years I have seen "SG" number on slab a couple times.

    certainly there was more on the slab. do you remember the text?

  • CoinOMCoinOM Posts: 72 ✭✭

    I would have my report tomorrow. The person who did the test said "we complete the test and coin was 90% aluminum"

  • CaptHenwayCaptHenway Posts: 33,816 ✭✭✭✭✭

    Say what?

    Numismatist. 54 year member ANA. Former ANA Senior Authenticator. Winner of four ANA Heath Literary Awards; three Wayte and Olga Raymond Literary Awards; Numismatist of the Year Award 2009, and ANA Lifetime Achievement Award 2020. Also won the PNG's Robert Friedberg Award for "The Enigmatic Lincoln Cents of 1922," Available now from Whitman or Amazon.
  • TomBTomB Posts: 22,957 ✭✭✭✭✭

    @CaptHenway said:
    Say what?

    Ditto!

    Thomas Bush Numismatics & Numismatic Photography

    In honor of the memory of Cpl. Michael E. Thompson

    image
  • ambro51ambro51 Posts: 14,343 ✭✭✭✭✭
    edited June 21, 2026 12:53PM

    Note similar results here

  • coinbufcoinbuf Posts: 12,445 ✭✭✭✭✭

    Here we go again.

    My Lincoln Registry
    My Collection of Old Holders

    Never a slave to one plastic brand will I ever be.
  • braddickbraddick Posts: 25,102 ✭✭✭✭✭

    This is a great thread!

  • RedRocketRedRocket Posts: 1,448 ✭✭✭✭✭

    @CoinOM said:
    I would have my report tomorrow. The person who did the test said "we complete the test and coin was 90% aluminum"

    If by, "90%" you mean 97.5% and if by, "aluminum" you mean zinc then I am in 100% agreement with you.

  • jonathanbjonathanb Posts: 4,039 ✭✭✭✭✭

    @ambro51 said:
    Note similar results here

    That's actually not completely useless. If you take out the elements that we know aren't present, and then scale the rest up to 100%, the ratios match the reference lines fairly well.

    Of course that only works if you know what elements are supposed to be present. for the OP's coin, it's probably safe to assume we're only talking about copper and zinc.

    On the other hand, this whole discussion started because the XRF results aren't reliable when examining thickly plated coins. A new set of XRF results won't be any more reliable than the first ones. It's a shame that neither NGC nor PCGS got specific gravity values before slabbing.

  • ambro51ambro51 Posts: 14,343 ✭✭✭✭✭
    edited June 21, 2026 1:48PM

    The XRF done is useless. Crack it out and have XRF done again with shots on the obverse and reverse. Believe what the British Museum tells you……. You can’t do XRF through a slab. It can’t make sense of it and calls it 90% aluminum…which is Exactly what the XRF done for the OP indicated.

  • jmlanzafjmlanzaf Posts: 41,018 ✭✭✭✭✭

    @ambro51 said:
    Note similar results here

    This.

    While it is possible to get XRF results through the slab, you can also get spurious results.

    If it were Aluminum, it would be almost 3x thicker than a zinc coin and 3.5x thicker than copper.

    It is absolutely 100% NOT aluminum.

    All comments reflect the opinion of the author, even when irrefutably accurate.

  • MsMorrisineMsMorrisine Posts: 39,370 ✭✭✭✭✭

    aluminum is a lightweight material. lighter than zinc. i agree that it would have to be much thicker to be of the given weight.

    https://en.wikipedia.org/wiki/1974_aluminum_cent

    Mass 0.937 g

    Current maintainer of Stone's Master List of Favorite Websites // My BST transactions
  • ByersByers Posts: 1,936 ✭✭✭✭✭

    @jmlanzaf said:

    @ambro51 said:
    Note similar results here

    This.

    While it is possible to get XRF results through the slab, you can also get spurious results.

    If it were Aluminum, it would be almost 3x thicker than a zinc coin and 3.5x thicker than copper.

    It is absolutely 100% NOT aluminum.

    Correct. Obviously.

    If it were aluminum it would be struck on a planchet that was thicker, considering the stated weight.

    My 1977 Aluminum Cent, that Heritage sold for $50k, only weighed 1 gram since it was the same thickness as a regular copper planchet.

    mikebyers.com Dealer in Major Mint Errors, Die Trials & Patterns - Author of NLG Best World Coin Book World's Greatest Mint Errors - Publisher & Editor of minterrornews.com.
  • MsMorrisineMsMorrisine Posts: 39,370 ✭✭✭✭✭

    @jonathanb said:

    @ambro51 said:
    Note similar results here

    That's actually not completely useless. If you take out the elements that we know aren't present, and then scale the rest up to 100%, the ratios match the reference lines fairly well.

    Of course that only works if you know what elements are supposed to be present. for the OP's coin, it's probably safe to assume we're only talking about copper and zinc.

    On the other hand, this whole discussion started because the XRF results aren't reliable when examining thickly plated coins. A new set of XRF results won't be any more reliable than the first ones. It's a shame that neither NGC nor PCGS got specific gravity values before slabbing.

    wrong is wrong. scaling up is improper as those can't be trusted either

    Current maintainer of Stone's Master List of Favorite Websites // My BST transactions
  • ambro51ambro51 Posts: 14,343 ✭✭✭✭✭

    Whoa. The British Museum data PROVES the XRF reads a slab as 90% aluminum. What part of this fact do you see not applying here???????

  • CaptHenwayCaptHenway Posts: 33,816 ✭✭✭✭✭

    @ambro51 said:
    Note similar results here

    Somebody please repeat the test on an empty slab.

    Numismatist. 54 year member ANA. Former ANA Senior Authenticator. Winner of four ANA Heath Literary Awards; three Wayte and Olga Raymond Literary Awards; Numismatist of the Year Award 2009, and ANA Lifetime Achievement Award 2020. Also won the PNG's Robert Friedberg Award for "The Enigmatic Lincoln Cents of 1922," Available now from Whitman or Amazon.
  • MasonGMasonG Posts: 7,015 ✭✭✭✭✭

    Without commenting on the effort of anyone in particular, this whole exercise seems to me so far to have been a perfect example of how to not figure out much of anything useful at all.

  • MsMorrisineMsMorrisine Posts: 39,370 ✭✭✭✭✭

    @CaptHenway said:

    @ambro51 said:
    Note similar results here

    Somebody please repeat the test on an empty slab.

    it could be gunned keeping it in the slab and just aim for the gasket part of the slab.

    and while I'm here, the specific gravity appears not to have been done.

    Aluminum . . . . . . . .. . . . . . 2.70
    Copper (bronze .900) . . . . .8.94
    Zinc (pure). . . . . . .. . . . . . .. .7.13

    Current maintainer of Stone's Master List of Favorite Websites // My BST transactions
  • MsMorrisineMsMorrisine Posts: 39,370 ✭✭✭✭✭
    edited June 21, 2026 4:42PM

    i'll reiterate - if the copper plating is really that thick then an xrf will likely show a very high copper content

    i've dissolved the zinc out of a zincoln with vinegar (acetic acid) and the thickness of the copper is thinner than a human hair. I forgot what it weighed but it was under 0.10 gram

    Current maintainer of Stone's Master List of Favorite Websites // My BST transactions
  • ambro51ambro51 Posts: 14,343 ✭✭✭✭✭
    edited June 21, 2026 5:07PM

    It should be possible to take an XRF shot into the deepest part of that “scratch”.

  • TomBTomB Posts: 22,957 ✭✭✭✭✭

    This is the thread that just keeps giving.

    Thomas Bush Numismatics & Numismatic Photography

    In honor of the memory of Cpl. Michael E. Thompson

    image
  • MasonGMasonG Posts: 7,015 ✭✭✭✭✭

    @TomB said:
    This is the thread that just keeps giving.

    Yeah, but what?

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