Odd 1973 D zinc cent, not plated

Not at all. It sounds like an endpoint for me. The point I can't figure is if the machine said it was "Just zinc" , and if it is the same diameter and height( as it appears), how could it weigh 3 grams instead of about 2.5gram? If only zinc, it would have to be wider or higher than a normal cent size. I would suspect the machine if it is a detector intended for bullion, as it would not be calibrated well for zinc as it is not near a density to be used as a fake for silver. Anyway , let us know if you find more info. Jim

 

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Thanks for your help!

 

@desertgem and @Kentucky , NOW I completely understand why someone would use mercury. I never knew that mercury amalgamated. That's pretty cool.

 

The Sigma Metalytics machines are interesting

http://www.sigmametalytics.com/

If you read carefully

and

which implies the standard wands only measure to a depth of 0.5mm - still WAY thicker than any plating. The technical guide discusses the sensitivity for each of the measuring devices.

 

Well guys I'm kind of at a loss on what my next step should be. Assuming the machine the dealer used is correct, I have a 100% zinc 1973 penny, that shouldn't exist. I can't see why anyone would have counterfeit a 1973 penny!

Would sending this thing off to be graded help any?

 

The first machine is what my dealer used! I had no idea what it was called. Thanks for the link!

 

Grading and attribution are two different things. Perhaps someone on the forum will be able to suggest what your next step should be.

 

Choose 1 of these 2 top grading and attribution services... then get back to us!
(I still say it is plated)
https://www.ngccoin.com/submit-coins/how-to-submit.aspx
and
https://www.pcgs.com/services

 

Yes, that was what I was referring to in post #21. It seems to use ultrasound transmission time to determine the metal(s), but it has to be specific for silver and the Gold-platinum group to be accurate. It is said to be effective for bullion, but I have not seen a "blind test" in any reviews. Maybe someone in the bullion group has one and can comment. So I do not see how it could be determined to be zinc. Copper detection is more realistic, and the instruction manual on that post mentions copper in jewelry as problematic. Most experts you would send to would do weight, size ( compared to a known cent) and specific density to compare with zinc and/or copper. Most large universities with a geology or mining studies could probably d it, maybe even 1 or 2 members that have such equipment. Alas, mine does not. Jim

 

I guess my next step is to get it evaluated. Any recommendations on which company to use?

Honestly if this thing could be potentially be valuable, I'm a little leery of trusting the post office.

Again, I'm completely new to all of this.

 

Attributed

Here is the information..
https://www.ngccoin.com
Or
https://www.pcgs.com

I honestly don't think you have anything special but please choose one of those 2 companies and get back to us ASAP

 

Thanks for the info!

Im aware I'm going to have to pay someone to evaluate the coin, and thats fine. I travel often and would like to hand deliver it if possible. I'm a bit scared of throwing it in an envelope and trusting the mailman lol!

 

Yes please do that. You don't want to poison the mail person with mercury

 

From what I've learned on here I'm guessing your right. But since Im now retired and have nothing better to do, an excuse for a road trip sounds good!

Thanks again for the info. I'll follow up with my results. Either I'm going to be rich or you all will have a good laugh at the new guy lol!

 

HAHAHAHAA

 

I found a PCGS dealer about 3 hours away from me. Can they evaluate my coin or does it have to go to the main headquarters? https://www.pcgs.com/dealers/Detail.aspx?d=1483&log=True

 

The dealer may give you an opinion, but it would have to go to PCGS to get their attribution service. The PCGS dealer could send it to them for you. I would have to go with the general consensus though that the coin is plated. There would be no reason for the mint to have a zinc planchet, and even if it was zinc it would be much lighter than a regular composition cent.

 

A couple things to consider before spending (wasting) $50+ to have your coin returned as “Altered”.

IT CAN’T BE ZINC

• You said your coin weighs 3 grams, which is what a regular cent would weigh on a scale with low resolution. (You should use a scale that weighs to 0.1 grams or 0.01 grams, but it doesn’t matter for this discussion).
• The density of zinc is approx. 20% less than copper, so if your coin was zinc, and weighed 3 grams, it would have to larger than a normal cent. If it’s the same size as a normal cent, then it would weigh approx. 2.5 grams (which, by the way, is what a current copper plated zinc cent weighs. Love it when science and math come together). @desertg pointed this out in an earlier thread
• In 1973, the mint was not using zinc planchets. Not for Domestic production and not for foreign contracts. (Knock your socks off looking through this list to see if you can find something that matches your size, weight and composition from the early 70’s https://minterrornews.com/foreign_coinage_production_figures.pdf ). So, where did it come from?
• Also, as @desertgem pointed out from the link @Burton Strauss III posted, the Sigma Analytics machine is calibrated for specific gold and other precious metals. You can’t just pop another material and expect to get anything accurate. The machine doesn’t work that way.

So, the chemistry and math says it can’t be zinc, a number of knowledgeable numismatists on this site have opined that it is plated or reacted with Mercury, and we know that plating cents is a common HS chemistry experiment that has been used for years (Coin talk seems to get a question about plated cents at least weekly, since I’ve been on here).

Save yourself some time and money. It will come back as altered. If you really feel like gambling, take your $50+ and buy lottery tickets or bet on the Cleveland Browns to win the Super Bowl next year. You’ll have a better chance of making some money. Or better yet, use it to buy a good bottle of bourbon.

I hope this helps. Best of Luck.

 

Yes it said it contained both metals, but what percentages. If it can really read through the plating it should've come back with 97.5% zinc 2.5% copper. If it came back with a high copper reading and a lower zinc reading then it's mainly just reading the outer plating and picking up traces of the core.

My advice for your next step would be to do a specific gravity test. If it's a regular cent and just played with zinc you'll get a reading very close to 8.83, if it's actually a zinc cent you'll get a specific gravity of just a little over 7.