I hope you all don't mind another.. I know nothing about coins! (I just toss aside anything interesting looking) Any thoughts on this 1982 Quarter with smooth edges and dark coloring?
Just a heavily-used quarter with environmental damage. Coins - especially heavy coins - used in machines a lot (such as slot machines) can lose their reeding. That could explain the smooth edge. The discoloration could have been caused by the coin being dropped on the ground and left for a period of time.