@CoinOM said:
Ok to summarize the data I also collected data from a 2016 penny on its own and with it in a polystyrene case.
2016 penny no case
Cu: 49.82%
Zn: 50.14%
2016 penny in case
Cu: 41.48%
Zn: 58.12%
1983 penny in case
Al: 90.85%
Cu: 5.15%
Zn: 3.89%
I will try to collect some more data with the XRF. I would like to do a CT scan on it as well to see if we can see the coating.
Just looking at the 2016 cent you used as a test piece, it is coming back at almost equal parts copper and zinc. The XRF isn't reliable for showing the true composition of a plated coin.
XRF is a surface test. That might be accurate for the surface of the plated coin.
Knowing the surface doesn't tell the whole story. To get a full picture of the coin, a specific gravity test is needed.
I made no comment on the SG test. Conductivity might also work.
I just wouldn't say that XRF isn't "reliable". XRF isn't "capable" of doing bulk analysis, whether plated or not. It's a surface only test.
All comments reflect the opinion of the author, even when irrefutably accurate.
So they want to help you but they never did a specific gravity test that would have answered every question. It seems like you just got a delay email and no one wants to bother.
Go easy on the OP. He could have thrown it away after being slabbed by NGC as a normal 1983 cent or quietly sold it as a bronze planchet as originally stated by PCGS. He sincerely seems to want to get all the information he can on the coin just for the sake of knowing and having it correct.
@TrickleCharge said:
Go easy on the OP. He could have thrown it away after being slabbed by NGC as a normal 1983 cent or quietly sold it as a bronze planchet as originally stated by PCGS. He sincerely seems to want to get all the information he can on the coin just for the sake of knowing and having it correct.
Based on the OP's good nature and ability to handle inquiries within this thread- whether sincere or sarcastic- leans toward the conclusion he doesn't need your help.
This is what the specialist from the company that analyzed the coin sent me. (He also used a 2016 cent as a sample of a modern coin.):
"Ok so XRF data came back and the two coins are identical. It looks like the coin being a thicker coating of copper is the likely option here. I will still do one more X-ray test but not looking promising based on the XRF data. "
Did they examine it out of the plastic? If so, might I ask,
(drum roll )
WHAT WAS THE SPECIFIC GRAVITY?????
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.
@CaptHenway said:
Did they examine it out of the plastic? If so, might I ask,
WHAT WAS THE SPECIFIC GRAVITY?????
That is, after all this time, still the only question that matters. It just seems so obvious that I cannot understand why one would not be done.
Not really necessary if it's shooting zinc with the XRF.
True, but there are always people who will deny the probable if it is not proven 100% with facts.
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.
Comments
I still haven't received a response from PCGS regarding my question about the basis for their change in attribution.
Doubtful and Debatable.
I made no comment on the SG test. Conductivity might also work.
I just wouldn't say that XRF isn't "reliable". XRF isn't "capable" of doing bulk analysis, whether plated or not. It's a surface only test.
All comments reflect the opinion of the author, even when irrefutably accurate.
You may doubt it, but you can't debate it. It is the ONLY definition of aluminum.
Of course, XRF measures electrons not protons, so...
All comments reflect the opinion of the author, even when irrefutably accurate.
Please don't continue to confuse and thus derail this thread by providing facts.
Thanks, in advance.
Apparently, that extremely complex and confusing test is beyond the capability of the team undertaking this Herculean project.
For the love of God, from among whatever it is you're choosing to do- DON'T do a specific gravity test. That'd kill the thread for sure.
I nominate this thread for the forum’s Top 10 “The Dead Horse Has Been Beaten So Badly That He Might Have Come Back To Life” thread.
Mark Feld* of Heritage Auctions*Unless otherwise noted, my posts here represent my personal opinions.
An oldie but goodie...
it won't be over until the fat penny has rung
I've got the comment from PCGS:
So they want to help you but they never did a specific gravity test that would have answered every question. It seems like you just got a delay email and no one wants to bother.
In honor of the memory of Cpl. Michael E. Thompson
I decided to open the coin and conduct all possible examinations.
I'm afraid to ask, yet will do so. . .
What do you mean you "opened the coin"?
I see. The taco cents.
I guess you just made PCGS happy.
In honor of the memory of Cpl. Michael E. Thompson
I mean I would brake the slab.
Brake or break?!
Go easy on the OP. He could have thrown it away after being slabbed by NGC as a normal 1983 cent or quietly sold it as a bronze planchet as originally stated by PCGS. He sincerely seems to want to get all the information he can on the coin just for the sake of knowing and having it correct.
Based on the OP's good nature and ability to handle inquiries within this thread- whether sincere or sarcastic- leans toward the conclusion he doesn't need your help.
This is what the specialist from the company that analyzed the coin sent me. (He also used a 2016 cent as a sample of a modern coin.):
"Ok so XRF data came back and the two coins are identical. It looks like the coin being a thicker coating of copper is the likely option here. I will still do one more X-ray test but not looking promising based on the XRF data. "
Did they examine it out of the plastic? If so, might I ask,
(drum roll )
WHAT WAS THE SPECIFIC GRAVITY?????
That is, after all this time, still the only question that matters. It just seems so obvious that I cannot understand why one would not be done.
.> @Old_Collector said:
Not really necessary if it's shooting zinc with the XRF.
All comments reflect the opinion of the author, even when irrefutably accurate.
True, but there are always people who will deny the probable if it is not proven 100% with facts.
Nine pages of posts and I stick with PMD by some kid playing around with electroplating.