Hello Nathan W,
I remember an old story about two kids 10 or 11 years old, in Florida who were waking along a beach up along I believe up near Vero Beach (the 1755 fleet comes to mind) and after a storm saw a small hole in the grassy tuft of the sand. Upon excavating the hole they happed to find the remains of a rotted bag that contained clay marbles. Being kids and not thinking much about their find, proceeded to use the marbles as skipping stones. One of the boys had put three of the clay marbles in his pocket and forgot about them.
When he got home he put them in his desk drawer. Speed up the time by 20 years and the young man was going through his childhood drawers at his parents house and found the cay marbles. He was ready to throw them out when he noticed one had the tint of green. He chipped it way and it revealed an emerald. So did the other two marbles and then it hit him that they as kids had skipped 30 or more marbles that day.
I nearly bought a round diamond on ebay, that was the same size of a .31 caliber ball.
So I would keep what you found you can never know what it truly is?
Bests In Treasure
LUE-Hawn