Is this natural?

[East Kentucky Adventurer]

I was searching a shallow river bed in eastern Kentucky for river glass last weekend and this caught my eye. I tried to take a few pics that showed it the best. It isn't very heavy. Could it be bone?
The thickness is uniform and all of the edges are worn smooth. It has me puzzled...

Any ideas?

 

Amazon Forum Fav 👍

Family Maps of Hinds County, Mississippi, Deluxe Edition - Grab it through Amazon!