It is a 1980 P Jefferson nickel. I held on to it because of the black color. I have used some mild soap to see if the black washes away and it does not. I have no idea why it would be this color. I have heard of black beauties but those are all from the 40’s I think. I have had this coin quite a while and having insomnia tonight, going thru some of my coins I keep, I really looked at it and now I’m really perplex on wth is wrong with this thing? Idk if it’s a mint error or a circulated error. Monticello is a hot mess. I’m lost about it. Please help so I can get some sleep. Lol.
Three words Environmental Exposure Toning Clad coins and Nickels are composed of Cupronickel. It's a mixture of copper and nickel. The Copper will tone after long exposure to soil, sand, dirt and the elements. Here are many of my metal detected finds There's no way to clean them once they are toned. It's permanent! And on your Nickel MONTICELLO has circulation wear and tear/hits. Now you can go to sleep! Rest well.
Here is what a black beauty looks like. It is similar in color but shows no environmental damage like your coin.