More info:
It's a gold plated pillbox with no markings anywhere, the contents were dirt and small insects. The plating (which appears to have been painted on) flaked off the bottom a little when I was cleaning it. After it dried out the picture cracked at the bottom. I found it on local Park District property in a lightly-wooded area in the rootball of a young tree, about 4 inches down. The home on the site was built in the 1870's.
I use a Bounty Hunter Tracker IV.