Bilbo's Mithril shirt

Bilbo's Mithril Shirt was the unbreakable chain mail that Thorin II Oakenshield gifted to the Hobbit Bilbo Baggins.

It is unknown when it was made or where the Mithril came from but it is part of the Dwarven hoard of the Lonely Mountain (Erebor) and given to Bilbo along with a belt of pearls and crystals & a helm.

Many years later when Bilbo's nephew Frodo Baggins was chosen to destroy the Ring of Power Bilbo gave him his sword Sting and the Mithril shirt a good thing because it saved the Ring-bearer in the Mines of Moria.