Toadstones are the button-like palatal teeth of lepidotes, an extinct genus of ray finned fish from the Jurassic and Cretaceous periods.
However, throughout the Middle Ages and into the 18th century they were thought to be found in the heads of living toads and were highly prized for their supposed magical properties.
In the play As You Like It (1599), Shakespeare writes: “Sweet are the uses of adversity, Which, like the toad, ugly and venomous, Wears yet a precious jewel in his head.”
Sworders’ example, set in a high carat gold shank in the Tudor or early Stuart period, is pierced to the underside in the expectation that the stone’s protective powers would be increased on contact with the wearer’s skin. At some point in its life the ring had become too small for the owner to wear so instead it was fitted to a chain.
These are always desirable items - in March one sold for an unexpected £4200 at Reeman Dansie in Colchester - and this example offered on November 23 with expectations of £3000-5000 took £12,500.