The part that is crushed in a bit looks like some type of gemstone. The closest thing that I can think of when I see the texture is some kind of dark granite that I find around the shores of Lake Superior although I am not very good at identifying all the stones, these dark rocks I consider granite may not be granite at all. Nice, round find though! I think that it has the possibility of being used as a tool.

Thanks for using the #rockhound tag! Manually curated by @bitfiend and also with the @rockhounds account!