I found this penny that seems to be a big error? These pictures is the best that I could take of it. This penny has UNITED STA accross the and has the letter E below the A, and below the word UNITED you can see the outline of the eagle wing. The letters UNITED STA and the E are doubled.
Looks PMD to me, perhaps the cent was on a hard surface and had a quarter kind of on it, then something very heavy put on top or it was struck by a hammer.
The area between "LIBERTY" and "IN" is devoid of the substance. The edges of the raised areas covering LIBERTY appears to be transparent in the photos. If you were to check it with a heated needle to see if it will penetrate it, it won't affect any perceived value because this isn't a mint error.
A story from the mind of a mad man. From personal experience working on different things for some reason this little story popped into my head. I've seen a few glue remarks. And from seeing similar things, I thought this might be fun, This is pure assumtion. If it were in a Mechanics rack and the mechanic was repairing a cracked radiator after mixing some J&B weld to fill the crack. Their would be some left over on some cardboard or scrap pc left out on the cart where where a coin could easily come in contact with his change from the pack of cigs he had his assistant go get. So at some point while he was fumbling for a tool the J&B slid into a penny that got stuck to a quarter. Then at some at some other point the change was pulled apart for future purchase. Theirs a 110 different products that would give it a hard steel feel. But always double check with more than 1 person. You never know if the first one is being truthfull. You never know. Of course my story left out the color difference being J&B would dry a dull gray.