Pretty tough to ID from the picture. You will have to just keep spinning it around while looking at it with a loupe and see if there are some letters or something you can find to identify it. Good luck.
Beach High Banker, Sweep Jig, Whippet Dry Washer, Lobo ST, 1/2 width 2 tray Gold Cube, numerous pans, rocker box, and home made fluid bed and stream sluices.
Probably a coin (50 cent piece or dollar) partially melted in a fire and a little silver polish or filing should bring out the silver color to that area and confirm it. Or check for steel content with a magnet. If it sticks it's junk.