In J.R.R. Tolkien’s legendarium, what substance is mithril?

In J.R.R. Tolkien’s legendarium, mithril is a precious metal.

Mithril is a rare, light, and exceptionally strong metal found in Middle-earth. Its name comes from Sindarin and is commonly explained as meaning “grey glitter.” The metal is most famously associated with Khazad-dûm, the great Dwarven realm later known as Moria.

In The Lord of the Rings, Bilbo’s mail coat is made of mithril, and Frodo wears it during the quest. The coat is light enough for a hobbit to wear but strong enough to protect him from a deadly attack. Mithril also appears in descriptions of Númenórean and Elven craftsmanship.

Readers sometimes treat mithril as a general synonym for magical material, but Tolkien presents it specifically as a metal with unusual physical properties. Its scarcity, beauty, and connection with lost Dwarven mines make it valuable throughout the stories.