MYSTERY METAL

The pebble is funny, I race with a guy who just installed hydramat in his fuel tank. He pull a ROCK out of the tank as big as his fist! It has been in there for 30 years! He dragged the car out of a Georgia wrecking yard and fixed the body. Never looked inside the tank. Perfectly clean except the boulder! Looks like bearing material or the flat spring from timing chain tensioner, but that would be magnetic.