Not saying that the large coin is this or not but here is a quick story.... Was out with my brother, I was coin shooting and had the detector eliminating iron. My brother the practical joker he is said try over there, "I was getting some weird hits but couldn't find anything"... I went over the area and didn't find anything. He proceeded to go over it again, gets a hit, digs a plug and puts on an act... then flips me this silver dollar sized coin. I said I had just gone over that spot and didn't get a hit... So I put the coin on the ground and swing over it with my detector and it hits as iron... pull out a magnet and it doesn't stick..... Then I get the real story: This was a chinese coin/token that you could buy at a chinese restaurant for 50cents... cool looking too, dragon on one side some rulers face on the other and dates ranging in the 1600's...... Must be some cheap stainless to hit in iron, look like silver and rust! I took mine to plant in VB and just walking around for a few hours in the mist, it was all rusty!
Cliff