# Tongue stones

**Glossopetrae**

**Known today as.** Fossil sharks’ teeth, called tongue-stones, and by the Germans adders’ tongues.

Kind: Amulet

## What was it used for?

Worn as amulets against poison, and hung from the “adder-tongue trees” set on the side-tables of the courts of Europe, to be dipped in drink and draw out any poison.

## What does modern science say?

In 1667 Nicolas Steno, setting them beside the teeth of a shark’s head he had dissected, found them as like “as egg to egg,” and judged that those who called the larger tongue-stones sharks’ teeth were not far from the truth.

## What lore surrounds it?

Most came from Malta, where they were called St. Paul’s tongues: some held them the tongues of the island’s snakes, which the saint cursed after a viper bit him there. Pliny reports the belief that they fell from the sky during the moon’s eclipse.

## What did the older authorities say?

**Pliny.** Reports that the glossopetra, which resembles the human tongue, is said to fall from the heavens during the moon’s eclipse, and is held highly necessary for selenomancy, divination by the moon.

**Pliny.** Pliny already has the tongue-stone: “Glossopetra, which resembles the human tongue, is not engendered, it is said, in the earth, but falls from the heavens during the moon's eclipse; it is considered highly necessary for the purposes of selenomancy. To render all this however, still more incredible, we have the evident untruthfulness of one assertion made about it, that it has the property of silencing the winds.” The Catholic Encyclopedia would class the later use under the amulets “worn as a remedy or preservative against evils or mischief.”

## Sources

- Pliny the Elder, *Natural History*, book 37.
- Steno, N. (1667). *Canis carchariae dissectum caput*. Florence.
- Pliny the Elder, *Natural History* 37.59, trans. J. Bostock & H. T. Riley (1855), Perseus Digital Library.
- *The Catholic Encyclopedia* (New York, 1907–1914), “Superstition.” newadvent.org/cathen/14339a.htm
- Zammit-Maempel, G. (1975). Fossil sharks’ teeth: a medieval safeguard against poisoning. *Melita Historica* 6(4): 391–410.
- Zammit-Maempel, G. (1978). Handbills extolling the virtues of fossil sharks’ teeth. *Melita Historica* 7(3): 211–224.

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*Tongue stones.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-03. The Thinking Press. https://thethinkingpress.org/materia-medica/glossopetrae

Historical description, not medical advice.