1982 zinc lincoln penny

Good evening Gents & Gals, I have a question I hope somebody can answer. I have a 1982 zinc lincoln penny, I found it sorting through my coins by weighing them in my scale and it reads 2.5 grams. So, as far as I know, these pennies are 95 percent zinc and 5 percent cooper plated am I right there? Well I have the privilige of checking the exact elements all of my jewelry has so I went ahead and checked the penny. It turns out it is 51 percent Zinc, 47 percent cooper and 0.39 percent Iron, Any thoughts? I uploaded a pic so you guys can see.

 

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There is 3.61 percent unaccounted for.. what is that then?
Also.. you need to explain what kind of device you have. I'm not a jeweler or metal analyst!
Have you tried another 1982 Cent or plated Cent to see if you get similar results?

 

What kind of device do you have? A device that enables one to look at elemental composition of metals sounds like a dream come true!

 

Sorry, I should have mentioned the device I was using in the first post. It is a Thermo Niton XL2, I use it at work to check the contents of metals ( I buy gold, silver, platinum) I actually have checked other coins that I have been curious about and they are all 95% percent copper or whatever the correct specs are that I find while doing my research except for this one.

 

The instrument analyzes the surface of an object and a cent coin should show essentially 100% Cu on the surface and if you scratch the copper away, you should get 100% Zn. Perhaps @BadThad could offer an opinion.

 

XRF technology only tests the surface of the material. Some material requires grinding of the surface for an accurate test. Materials with coatings/plating can skew results.

 

After working buying Gold and Silver for the past year I have learned there is a difference in the readings by the way you aim the analyzer. To get the best reading you would get the object on its side to kind of go through the whole internal material.

 

It will NEVER "go through the whole internal material."

 

I will test and take pictures of other 1982 pennies that I have in my possession on Tuesday and upload pics for you guys to see and perhaps chip in on my findings. Thanks for replying!

 

While you're at it, how about checking a 1981 and 1983 cent if you have them. I'm just curious.

Chris

 

Here's a chart from the Red Book .

 

I have a coin you can check and I'll send it your way . It's a 1864 two cent piece, I think is on a 1863 pattern planchet ( copper ) .

 

Those testers do penetrate slightly into the surface. If it is that would explain the odd reading. It is seeing the zinc below the surface.

And wouldn't Ir be Iridium? It seems to use the standard abbreviation for the other elements. Iron would be Fe.

 

You are getting some penetration though the plating is all. Ir is Iridium, not iron. It's a false reading, probably due to an escape peak.

 

Send me a message so I can see about checking this out.

 

UPDATE***


Ok guys, I did some more testing, I did the same 1982 zinc 2.5gram penny along with another 1982 penny, 1981 & 1983 penny. To my surprise I got the same reading, well slightly the same on a 1983 D penny I will show you in a bit. As for the othe 2 pennies i got 95 percent cooper & 5 percent zinc, as it should be. Feedback is greatly appreciated.

 

Jackie Cooper?

 

Getting a little jumbled here. For a 1983 cent you got a reading of 95/5 Cu to Zn?

 

Sorry, I got 95/5 cu & zn on a 1981 & 1982 penny

The other 2 were 46/53 (the 82 penny in question) & 41/58 was a 83 penny