aluminum core bronze 1973

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Some time ago I traveled to Cuba and bought almost 500 cents for less than 5 dollars. Just the other day I noticed a strange color in this one, so wash it. what a surprise. I'm a copper and bronze sculptor, I know it's aluminum. But I do not find much information about it, it weighs less than it should and it is not magnetic. Can someone give me some information, I'm a rookie

 

Well how much does it weigh?

Looks like corrosion due to Environmental Exposure.

 

I agree looks like corrosion which means lost weight. I will not believe aluminum without a scan for metal content. Weight?

 

Aluminum? I thought the only aluminum cents were minted in 1974. Wasn't there also a bronze-clad steel trial piece?

 

What does it weigh?

 

http://lincolncentsonline.com/Experimental Cents.html

https://www.coinworld.com/news/us-c...bVVbNu3AeFgYBRb1x1nQ8GhbHaMGwkBMnBW_kKt-1i3oU

 

Honestly, it looks like a mercury copper amalgam which was sprayed with water... back in the day, we used to do that to cents.

 

An aluminum cent would weigh about a gram and a half. I'm betting this one still weighs considerably more than that, even though most of its original surface has been etched away.

 

All aluminum would weigh just about 1 gram. The Toland 1974 aluminum cent weighs just slightly less than a gram.

 

The link up above (to the list of experimental cents) shows a 1942 aluminum test with a weight of 1.5 grams. I thought I remembered the 1974 cents being just under a gram, as you say, and I see that's the generally accepted weight. I wonder if the listing for the 1942 cent was wrong, or if it was much thicker than the 1974 test?

 

the core is bronze, the layer is aluminum, weighs 2.4 grams.

 

Working with aluminum antenna and masts I haven't seen aluminum with that color and pattern. A plating of zinc is easily done in high school chem labs and that is my guess on it. Jim

 

Corroded cents are common, and can look like this, especially if the copper gets preferentially dissolved from the bronze. It's also possible for other materials to be deposited on the coin.

"Aluminum-coated bronze" isn't a composition that's ever been used or even tried for cents, as far as I can tell.

I respect your experience with metalworking, but I really think you're reaching the wrong conclusion here.

 

You started off with aluminum core bronze coated and now are at bronze core aluminum coated??? How about corrosion?

 

Valuable points of view, I suppose you do not know with certainty until you take it to a specialist. I will comment on the results.

 

It seems to me that either way, if the core is bronze, it is plated outside of the mint whether it is aluminum or zinc over the bronze, and has no value as damaged. Zinc is several times more reactive to acid than aluminum is due to its oxidation protection. A drop of acid on the area ( with a faucet running in the sink) can help. Drop a drop of hydrochloric acid or vinegar if not available. The drop of HCL would show tiny bubbles on zinc and no effect on aluminum until many times longer. This would avoid the cost of XFR testing and even though a coin dealer will say his gold/silver checker can tell, they are not calibrated for the base metals. IMO. Jim

I am 99+% sure it is zinc, see these experiments. When I have to teach a college chem class due to another teacher absence, These cents are in their lab drawers.

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

 

I wonder how many members have hydrochloric acid in the house?

 

It was on sale , I had to have it

 

I'm actually out. I had a big jug of muriatic acid (slightly lower concentration and purity), and it apparently wasn't vapor-tight, so it corroded everything around it in the garage. (I ended up using it as toilet-bowl cleaner.)

I do have sulfuric acid (drain cleaner) and various chlorides, so I can whip some up if I need it. Or run to the hardware store.

Nitric acid, that's the one that's hard to come by.