It's not aluminum. It's not silver. To be silver, it would have to be struck on a 1964 or before dime planchet. And then you wouldn't have full cent rims, the letters would be into the edge and it would weigh 2.5 (not because it was zinc, but because silver dimes weighed 2.5g). Not likely that there would still be a 1964 silver dime blank in a bin full of pennies in 1981. Aluminum cents are a little less than 1 gram, and while there really aren't any in circulation, it would be illegal to own. This coin was plated with something.
Doing the process can be, but the cent is not. Mercury amalgamates with copper, silver and gold which means molecular bound. You would need high heat like a torch to set the mercury free as a vapor, which is dangerous. Many "Real gold miners" still use the element to collect tiny gold dust particle and then heat the mercury out into air so a small lump of gold remains. There are a couple of do-it-yourself Youtube videos showing them doing it and talking while they do, of course they forget everything the next day.
I had a 1943P that looked just like it. I'm thinking I just hit the motherlode the a magnet shot me down. Someone has either chromed it or used a stainless core. Keep on collecting. Regards, The General
I have this exact same penny except mine is magnetic and weighs 3.15 grams. Very shinny on both sides and has no mint mark.
It's a penny. Keep it if it looks cool. It's not worth anything. (.01 cent) Very few things are magnetic. The most common are iron and nickel. Steel is magnetic because it has iron in it. US nickels are not magnetic because they are 25% nickel and 75% copper. So the plating could be the reason why your silver looking penny is magnetic. (Cobalt is magnetic, but it is unlikely to be on your coin.)
Please start a new thread so as not to hijack this one. Post photos in full size of both sides and state or ask questions clearly. It's probably plated and welcome to CT.