Police in Vero Beach, Fla., charge Christopher William Saunders stole a rare gold coin worth $9,000.
But Saunders apparently didn't know what he had.
Investigators say he sold it to a nearby antique store for less than 170 bucks.
To get the coin appraised, the store owner took it the coin shop where it was originally stolen.
That coin was minted in 1752 and came off a Spanish treasure ship.