Mithril is the fictional metal used for Bilbo and Frodo’s coat of mail in J.R.R. Tolkien’s legendarium.
Mithril is a rare, exceptionally light, strong, and valuable metal first associated with the Dwarves of Moria. Its name comes from Sindarin and is commonly translated as “grey glitter.” The Dwarves call it Moria-silver, reflecting its connection with the mines beneath Khazad-dûm.
Bilbo receives a mithril coat from Thorin Oakenshield’s treasure hoard in The Hobbit. He later gives it to Frodo, who wears it during the quest to destroy the One Ring. The coat protects Frodo from a spear thrust during the battle in the Chamber of Mazarbul.
Mithril is sometimes confused with other special substances in Tolkien’s writings, such as galvorn, a dark metal created by Eöl, or the Silmarils, which are jewels rather than metals. In Tolkien’s later history, mithril becomes extremely scarce after the Dwarves awaken the Balrog in Moria.