✅ SOLVED found on a gravel bed.

[captain redbeard]

feels hard like stone, but I can "dig" into it with my nail like its really dried clay. I wouldn't wear it, its hideous, but the hole is what caught my attention I don't see many holes. Is this just naturally made?

 

[Treasure_Hunter]

Natural, I found a lot of them in Missouri. Look at the hole, no sign of drilling..