Toad stones are the button-shaped teeth of the fossil fish Lepidotes. In folklore they were once thought to originate from the heads of living toads.
Toads were of particular interest to medical practitioners in the past. People believed that concoction made from pulverised toads protected against plagues since the toad’s warty skin resembled spots that are developed by plague victims. The toad powder was placed in amulets and worn around the neck or wrists.
Some people thought that the fossil fish teeth are petrified eyes of serpents and hoped they would protect them from anything evil.