J.R.R. Tolkien>
The Silmarillion
Anglachel was the sword forged by Eöl from the metal of a meteorite. It was part of a pair from the same meteorite, the other being Anguirel. Eöl gave it to Elwë as payment to live in Nan Elmoth.
The sword was later used by Beleg when he sought out to find Túrin for the second time. This was all despite Melian's warning that the fell spirit of Eöl was harbored in it. Túrin, beaten scared and senseless by his Orc captors, slew Beleg in a fit of madness with the sword. After this the sword broke and Túrin had it reforged in Nargothrond, renaming in Gurthang ("Iron death").
The deeds of Túrin with the blade became legendary and he soon became known as the Mormegil, "The Black Sword". Eventually Túrin turned the blade on himself after he found out the death of his beloved Níniel and of Morwen. The sword broke as he threw himself upon its point and was buried with him.
There he drew forth his sword, that now alone remained to him of all his possessions, and he said: 'Hail Gurthang! no lord or loyalty dost thou know, save the hand that wieldeth thee. From no blood wilt thou shrink. Wilt thou therefore take Túrin Turambar, wilt thou slay me swiftly?
And from the blade rang a cold voice in answer: 'Yea, I will drink thy blood gladly, that so I may forget the blood of Beleg my master, and the blood of Brandir slain unjustly. I will slay thee swiflty.'
-J.R.R. Tolkien
The Silmarillion