That's fantastic, what a find. Would love to know who wore that around their neck and when! I bet there's more too!!
Looks like a rock hammer in a gold pan?
You might check to see if there were old schools in your area that had some kind of "miner" nickname or mascot.
It is a souvenier miniature gold pan. Like something that you would get at a gold panning consession or GPAA gold show.
There might even have been small flakes of gold cemented in the depressions that you call rocks.
Many of the old time gold pans were made of copper so they wouldn't rust.
Very KEWL for a MD find!