Swords
Swords at all times have been possessed of magical qualities, but the belief possibly indicates stages of development. The description of the sword of Perseus as a form of diamond, suggests that the story had its origin in the Stone Age. It is reasonable to presume that the later improvements were such an advance that they suggested supernatural origin; e.g., the sword of Siegfried, the name of which was Balmung or Gram (literally “grief”).
The sword was reputed to be made by Wieland Smith, the Vulcan of the Scandinavians. To test the blade he tried it on Amilias, a brother smith, cleaving him through helm and armour down to the waist, but the cut was so fine that Amilias was not aware that he was wounded until he attempted to move, when he fell in two pieces.
Arthur’s sword Excalibur (liberated from the stone) is a later development, as the magical property was in the sheath, which rendered the wearer immune from injury. Arthur’s undoing was the result of losing the sheath, though he retained the sword.