I am hoping this is the last coin that I need assistance on for a while. I have been able to identify the rest, but this one is eluding me. At first I thought 14th century Russian and then my mind was telling me this coin looked a lot like early Mongolian coins. After that, I saw features that looked like it could be tied to a number of countries. I really am at a road block here. I appreciate any help that you might give.
The coin measures 15-16mm depending on the point of measurement. I don't have a way to weigh it, but it is very light.

