Didn't think much about this . One person said it might be part of a confederate buckle. It was found on a early site in this context. With these other early relics. That's a S.C. Button in the pic that's toast.
Cloak Clasp would be a very good guess with the attachment rings at 9o'clock and 12o'clock with it face up.
So go back and find the other one.
Very cool find!!