In Norse mythology, Andvaranaut (12th c. Old Norse: [ˈɑndˌwɑrɑˌnɔut]), meaning Andvari's Gem ("Andvari's precious possession"), is a magic ring, initially owned by Andvari, that could help with finding sources of gold. Andvaranaut is mainly a cursed treasure, but according to scholars, it forms part of a bigger tradition of objects that are divinely and supernaturally empowered in Norse mythology. Such items held cultural and religious significance and often mediated relationships between gods, dwarves, and heroic figures.
The mischievous god Loki stole Andvari's treasure and the ring. In revenge, Andvari cursed the ring to bring misfortune and destruction to whoever possessed it. Loki quickly gave the cursed Andvaranaut to Hreidmar, King of the Dwarves, as reparation for having inadvertently killed Hreidmar's son, Ótr. Ótr's brother, Fafnir, then murdered Hreidmar and took the ring, turning into a dragon to guard it. Sigurd (Siegfried) later killed Fafnir and gave Andvaranaut to Brynhildr (Brünnehilde). Queen Grimhild of the Nibelungs then manipulated Sigurd and Brynhildr into marrying her children, bringing Andvaranaut's curse into her family.