Mithril is a fictional metal found in J. R. R. Tolkien's Middle-earth writings. It is described as resembling silver, but being stronger and lighter than steel. It was used to make armour, such as the helmets of the citadel guard of Minas Tirith, and ithildin alloy, used to decorate gateways with writing visible only by starlight or moonlight. Always extremely valuable, by the end of the Third Age it was beyond price, and only a few artefacts made of it remained in use.
Impenetrable armour occurs in Norse mythology in Hervarar saga ok Heiðreks, a story that Tolkien certainly knew and could have used for his mithril mail-coat. Mithril is the only invented mineral in his Middle-earth writings. Chemists note mithril's remarkable properties, strong and light like titanium, perhaps when made into alloys with elements such as titanium or nickel, and in its pure form malleable like gold.
The scholar Charles A. Huttar states that Tolkien treats mineral treasures as having the potential for both good and evil, recalling the association of mining and metalwork in John Milton's Paradise Lost with Satan. The scholar Paul Kocher interprets the Dwarves' intense secrecy around mithril as an expression of sexual frustration, given that they have very few dwarf-women.
The metal appears in many derivative fantasy works by later authors.
Tolkien
Etymology
The name mithril comes from two words in Tolkien's Sindarin language—mith, meaning "grey", and ril, meaning "glitter".
Properties
In The Hobbit, Thorin Oakenshield described some Dwarven treasures as "coats of mail gilded and silvered and impenetrable" and "a coat of dwarf-linked rings the like of which had never been made before, for it was wrought of pure silver to the power and strength of triple steel." A little later the narrator describes "a small coat of mail, wrought for some young elf-prince long ago. It was of silver-steel which the elves call mithril".
In The Fellowship of the Ring, the wizard Gandalf explained mithril to the rest of the Fellowship in Moria:
The Noldor of Eregion, the Elvish land to the west of Moria, made an alloy from it called ithildin ("star moon"), used to decorate gateways, portals and pathways. It was visible only by starlight or moonlight. The West Gate of Moria bore inlaid ithildin designs and runes.
Abundance
In Tolkien's Middle-earth, mithril is extremely rare by the end of the Third Age, as it was now found only in Khazad-dûm. Once the Balrog destroyed Khazad-dûm, the kingdom of the Dwarves in Moria, the only source of new mithril ore was cut off. Before Moria was abandoned by the Dwarves, while it was still being actively mined, mithril was worth ten times its weight in gold. After the Dwarves abandoned Moria and production of new mithril stopped entirely, it became priceless.
Tolkien hints that mithril was found in the lost island kingdom of Númenor and the inaccessible continent of Aman.
The mithril-coat
The principal item made of mithril in the works of Tolkien is the "small coat of mail" that Thorin Oakenshield gave to Bilbo Baggins after it had been retrieved from the hoard of Smaug the dragon. Gandalf stated that the value of this mithril-coat was "greater than the value of the whole Shire and everything in it". The mail-shirt was first described in The Hobbit in 1937, but without any mention of mithril. Tolkien first described the shirt as being made of mithril in The Lord of the Rings in 1954, and it was retrospectively mentioned in the third, revised edition of The Hobbit in 1966. In the first 1937 edition, the mail shirt given to Bilbo Baggins is described as being made of "silvered steel".
Bilbo wore the mithril shirt during the Battle of the Five Armies. He donated it to the Mathom-house, a museum in Michel Delving. However he later reclaimed it, and took it with him when he left the Shire for his journey to Rivendell. There, some years later, he gave the shirt to Frodo Baggins when the younger hobbit embarked on his quest in The Lord of the Rings. Frodo wore the mail underneath his tunic and other shirt unbeknownst to the rest of the fellowship. The mail saved Frodo's life when he was struck by an orc chieftain's spear thrust during the battle in the Chamber of Mazarbul, and again when orc-arrows struck him while escaping Moria and while crossing the River Anduin.