The Victoria & Albert Museum
What is toadstone? During the Medieval and Renaissance eras, the stone was thought to have literally come from the head of a toad. That’s a lot of toads popping things out of their little skulls. As it turns out, toadstone has nothing to do with toads. It is, actually, the fossilized tooth of a fish—equally strange.
In the Thirteenth through Seventeenth Centuries, toadstones were assigned mystical properties—specifically thought to protect the wearer from being poisoned or getting kidney disease. Well, that’s oddly specific.
So powerful was the stone that it was said to give off heat when in the presence of poison and that, should the wearer be bitten, it could ward off snake venom. Furthermore, it was thought that toadstone could protect a pregnant woman from the fairies and demons which would want to steal the newly born child and switch it out for a changeling.
Here’s an interesting example of a toadstone ring. This, like most such rings, comes from Germany and dates to sometime between 1500 and 1600. The silver ring features a crown-shaped bezel which holds the toadstone. The shoulders of the ring are engraved with vines and flowers.
Toadstone is also known as “crapaudine” or “crappot”—charming names, which, oddly enough were assigned to it because of its rusty brown color. The proper name is “Lepidotes.”