Tonya, if you haven't already posted this on the North American artifacts, try it there. and IF it's stone, it could be a pendant, and that would make it a very nice find.
Hey TT, Is it heavy for it's size? It looks like it could be a sinker, but take a small screwdriver, file or something and try to scratch the surface Not to deface it to any degree, just a small scratch and if the scratch mark comes up shiny silver, i'd think it to be a lead sinker or some other soft metal... Keep Lookn
Not all the sinkers used in Oklahoma are all that soft... although made of lead... my father and myself have made numerous ones out of the lead weights from old wheel balances. The lead has something (perhaps tin) in it, and you definitely didn't use the lead tire weights to make the sinkers you bent the ears around the line! But I agree, it definitely looks like a lot of the sinkers I have in my tackle box, if it isn't stone......