Possible coin smaller then penny?

[RelicDude]

Yesterday I found this what's it on the surface while metal detecting I thought it was an Indian head at first but it's not ,it's smaller then a penny. I attempted to clean it to no avail there's no detail left except for a very faint 0 or an o. It's not a button there's no evidence of a shank ever being attached and it's about as thick as a fatty Indian. Any help would appreciated it has peaked my curiosity.

 

[cudamark]

The photo looks like a Lincoln cent to me. Regardless, it could be a 1856 flying eagle and it wouldn't be worth anything in that condition.