Mithril is the strongest metal known in Middle-earth. It looks similar to silver. It does not weigh much, and it is easy to make into things. Mithril is very rare and precious. It was only found in Khazad-dûm (Moria), where it was mined by the Dwarves, and (perhaps) in Númenor.
Influence on other fiction change
Mithril is now often used in other fictional works, usually as a strong and magical metal. It other fictional works, mithril is also sometimes written differently, for example as mythril or mithral.