Sky-iron was a type of meteoric metal that panserbjørne such as Iorek Byrnison used to create their armour. It was difficult to cut or break, with the exception of the subtle knife, which was stated to cut through sky-iron "like butter." For a panserbjørne, sky-iron was their soul, the equivalent of the dæmon found in humans.
Behind the scenes
- Although sky-iron is fictional, native peoples of the Arctic value meteorites, particularly the Cape York meteorite.