Any one have a clue to what this is....i was metal detecting along the Ohio river beaver, pa. It was about 5 inches deep about 2 feet away from the river...it looks to appear copper or bronze...it has a penny like appearance but looks more like a button. ..i can make out the crown symbol. .and the letter I can't make out...the condition looks to be pretty good a little aged...there a little green showing on surface in the back. It's about the size of a penny. I'm new to metal detecting so I have no clue what this is....anyone have any ideas?