Though the best metals for anything magic related, were Goblin Steel and Adamantine. Both metals that were incredibly rare, one of which I was the only one known to have any in the material plane. Both metals were made during a time when the world was new and magic filled the material plane in abundance. These metals were located in different areas of the world. Goblin Steel was only located in the Goblin homeland which was a good chunk of Western Europe, mainly in Germany. The Goblins had an extensive underground network that was connected in their homeland. By which they can mine the metal.