Toadstone

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Toadstone, or bufonite, is a legendary stone people believed lived in a toad’s head. It was said to be a cure for poison, like a similar stone once thought to come from frogs. In reality, toadstones are fossilised teeth from an extinct fish called Scheenstia (formerly Lepidotes) from the Jurassic and Cretaceous periods. They are small and were set in rings and amulets by medieval jewelers.

People linked the fossils to toads because toads have poison glands in their skin, so they thought the stone carried an antidote. The idea goes back to Pliny the Elder in the 1st century. Toadstones were believed to cure poison and epilepsy. By the 14th century they became popular in jewelry for magical protection, and folklore even said you had to take the stone from a live toad.

Toadstones are about the size of a fingernail and can be whitish brown, green, or black depending on where the fish lived. They were thought to work best against poison when worn against the skin, and some said touching the stone to a bite could cure it. Loose toadstones have been found in famous hoards, and rings with them survive in the Ashmolean and British Museums. They appear in literature, from Shakespeare to Cabell, and some toadstones were used in jewelry on the crown of Charles IV at Aachen Cathedral.