bufonite

Century Dictionary and Cyclopedia

1. n. Toadstone; a fossil consisting of the petrified teeth of Sphærodus, Pycnodus, and other Mesozoic ganoid fishes. It was formerly much esteemed for its imaginary virtues, and was worn in rings; it was thought to originate in the heads of toads.

Wiktionary

1. n. paleontology, obsolete A fossil consisting of the petrified teeth and palatal bones of fishes belonging to the family of Pycnodonts, whose remains occur in the oolite and chalk formations.

GNU Webster's 1913

1. n. (Paleon.) An old name for a fossil consisting of the petrified teeth and palatal bones of fishes belonging to the family of Pycnodonts (thick teeth), whose remains occur in the oölite and chalk formations; toadstone; -- so named from a notion that it was originally formed in the head of a toad.