I found this penny and I immediately noticed it sounded wrong; it was too high pitched. I looked closer at it and noticed that it was missing some details and it was thinner than normal but it has a normal diameter. I made a balance to compare it to the weight of a zinc penny and the error penny was lighter. It has some parts such as Lincoln's beard that are very detailed so I don't think it was acid dipped. The details seem to get lighter close to the edge of the coin. Is it stuck on a foreign planchet?