Found this coin a few days ago in a field... Took it home and
tried to clean it using peroxide. After a whole bottle it is much cleaner but there is no detail to be seen.. My question is, can you identify a coin by size.
In a word, 'no', not be size alone, but you can eliminate many types of coins that it isn't by knowing the size.
Your coin, if it's a coin versus a token or some other object, appears to be about 28mm in diameter.
That's a start.
Don.....
Might give electrolysis a try to knock off the outer layer. Some old silver coins that came up like that for me gave me a bit of detail after session in the bath.
There was not enough corrosion to hide anything from the start, so no amount of cleaning would have done anything.... just left a less corroded blank disk.
No, it definitely looks like an old coin, just a combination of circulation wear and corrosion from the ground. I just have to go into the next room here to prove they aren't an uncommon thing because I have a pile of them.