Possible silver coin?

[diver420]

Any ideas if this is a coin and what type?
I found this detecting a beach in St Martin on the French side.
It apears to be silver and the only thing that you can see is the letter
M on it. Sorry about the poor quality of the photo

 

[divewrecks]

Interesting, did it have a heavier crust layer on when you found it or was it just like the picture? If it was encrusted what color was it? Black? Greenish? How tall is it? Can't tell from the picture. If I thought you had a gram scale I would ask you what it weighed...

Thanks for sharing, Stan