Odd 1973 D zinc cent, not plated

First of all I have to admit I am a total novice when it comes to any kind of coin collecting. I found this cent while sorting through a couple thousand wheat cents i inherited.

After no luck with google, I took it to a local coin dealer and he weighed it and ran it through some sort of device that determines what metal a coin is made of. It came back as 3 grams and showed no traces of copper. His machine its zinc, its not magnetic and he said it was to heavy to be aluminum.

He said he couldn't find anything in his book about it and said that zinc wasn't used in cents around that time. He was stumped and even though i left with some answers, its still a mystery to me what exactly it is.

I hope my pics help even though they aren't the best. I put a regular penny next to it for comparison.

Sorry if i left out any necessary info but I will answer any questions the best i can.

Any info would be greatly appreciated!

 

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At 3 grams it weighs about what it should for a coin of that era. Therefore I would surmise that it is plated. There look to be some spots on both obverse and reverse where that plating is starting to rub off.

 

@pennylman1973
Plated with mercury... Don't touch it too much because mercury is poisonous!

We have seen many of these types of plated Cents on this forum.
Not a Mint Error.

 

How can it be a zinc cent when the mints didn't have zinc planchets in 1973?
It's damaged. (plated) It could be mercury. It also could be chrome or steel or silver or nickel.

 

So what drop it on the table and see if all the little drops that fall off come back to the main one??? At least that is what I did when I was a kid.

 

Plated w/ mercury as @paddyman98 said

 

His machine showed it as zinc because it was...copper cent plated with zinc. Done thousands of times a year in middle and high school chem classes.

https://www.sciencecompany.com/Turn-Copper-Pennies-Into-Silver-and-Gold-Pennies.aspx

 

okay guys (@paddyman98 , @lovecoinswalkingliberty ), teach me. Why mercury? Why not some other metal plating? Was this a popular science experiment back in the day?

Mercury is definitely a substance I wouldn't want to mess around with and I'm wondering why someone else did.

 

Such a Kool heavy metal..........

 

https://coins.thefuntimesguide.com/silver-penny/
"Countless U.S. pennies have been altered in appearance with the application of silver-colored (as well as gold-colored) metals.

Whether done as a science experiment in school or purely for the sake of novelty, plating pennies has long been a popular thing to do — especially for those who have no numismatic interest in coins and are unaware that plating coins is considered post-mint damage (or PMD), which can actually lessen the value of a coin."
Here is a quote from the sight, so yes, an science experiment or as an novelty

 

But why mercury? I get the plating portion of your response.

 

Thanks for all the replies!

Well i took a sharp knife and put a groove in the edge of it and looked at it with a magnifying lens and flashlight. Seeing as how its probably worthless i wasn't to worried about harming any value. I still don't see any copper color coming through.

I asked the dealer if the coin was plated with something would his machine be able to tell. He said yes and the did a test on a copper plated zinc penny to prove it.

He also said there weren't any zinc planchets used around that time which is what had him puzzled.

If it was dipped in mercury, would that give a false positive of zinc?

 

https://www.pcgs.com/news/authenticating-silver-pennies/

 

Its just like doing gold pennies

 

I agree. I can't see the machine calling mercury zinc.

 

Mercury doesn't plate , it amalgamates with the other metals. If you understand about metallic bonds ( different from ionic and covalent), mercury alloys with the metal through out the coin ( assuming enough mercury). whereas the process of plating is localized on the surface, no penetration/combining of the 2 metals. If a dentist does a metallic filling, he mixes the mercury and filling metal together. The amalgamating process allows the dentist to squish the mix into the cavity where it forms a tight fit and hardens. Although I haven't done it, Zinc amalgamates with mercury as well as copper. I am curious what machine the jeweler is using.

By the way mercury metallic form on the skin is not as dangerous as usually thought unless it is in the vapor stage or organic compounds. The loonies are the amateur gold miners, that use it and HEAT to separate gold from panned granules.

 

yup

 

Mercury amalgamates with copper very easily, all you have to do is put a drop of it on a cent and rub it with your fingers...feels really slippery and interesting. Don't worry about it hurting you, I did hit hundreds of times and it never hurt meeeeeeeeeeeeeeeeeeeeeeeeeeeee..........

 

Sorry for my ignorance but if his machine can detect what type of metal is in the center of a coin, or like a small bar of gold (his words), I wonder why it would come back as zero copper content if its a copper cent that has been tampered with?

To demonstrate his machine to me he scanned/zapped/analyzed (whatever the proper term is) a newer cent that was zinc plated in copper. The machine came back saying it contained both metals.

On mine however it came back just zinc. He told me the machine could see through plating and also detect the core metal. He was more puzzled than i was on the results. He initially assumed it was a zinc coated copper penny but after he scanned it he said that wasn't a possibility.

 

I hope I don't come across as argumentative, the coin dealers results from the machine just don't seem to make sense to me or him.