"That helm was wrought of grey steel adorned with gold, and on it were graven runes of victory. A power was in it that guarded any who wore it from wound and death, for the sword that hewed it was broken, and the dart that smote it sprang aside. It was wrought by Telchar, the smith of Nogrod, whose works are renowned. It had a visor (after the manner of those that the Dwarves used in their forges for the shielding of the eyes), and the face of one that wore it struck fear into the hearts of all beholders, but was itself was guarded from dart and fire. Upon its crest was set in defiance a gilded image of Glaurung the dragon; for it had been made soon after he had issued from the gates of Morgoth."
Unfinished Tales, Part 1, Ch 2, Narn I Hîn Húrin: The Departure of Túrin