Mjollnir = Thor’s hammer. It was given to him as a gift by two dwarfs. Thor used his hammer mostly for blessings and smashing the skulls of giants. When thrown, it would always hit its target and return to the thrower’s hand. Thor’s sons, Móði and Magni, gained possession of Mjollnir after his death.

Sign of the Hammer = like the Christian cross, the sign of the hammer was used for protection from evil, and as a blessing. It became customary around the tenth century for men to wear symbols of Thor’s hammer on chains around their necks.