Hunted (with permission) at 160 yr old church today. Didn't stay long but I did find these, in the same hole. My pointer kept picking more up but I was getting tore up by mosquitoes so I left.
1 pic is the front, and the other is the back. I assume its copper because they are green.
When you enlarge the 2nd photo, it looks like a piece of cast brass with an ornate design, or possibly a date or number on it. Can you make those details out with a magnifier?