Mjölnir or Thor's hammer is an artefact from Viking era. It was made by two dwarfs Brokk and Sindri as a gift for the gods. It was unbreakable, always hit its target and then it returned to its owner's hand and it could scale down so it could be worn on the neck. It was so heavy that only Thor could pick it up
People wear this pendant as a symbol of strength and it serves as a protection from all the evil things. Some sources say, that it was a viking response to the christian crosses.
But enough mytology, let's make one! :)