Angrist was the knife of the Elf-lord Curufin, but was taken from him by the Man Beren after Curufin tried to kidnap Luthien and kill Beren. Made by Telchar, a dwarf of the Blue Mountains.
That knife was made by Telchar of Nogrod, and hung sheathless by his side; iron it would cleave as if it were green wood.Silmarillion Page 215
Then he drew forth the knife Angrist; and from the iron claws that held it he cut a Silmaril.Silmarillion Page 219
The knife Angrist snapped, and a shard of the blade flying smote the cheek of Morgoth.Silmarillion Page 220