Heimdall returns Brisingamen to Freya
Brisingamen is said to be the (principally amber) necklace of the goddess Freya from Norse Mythology. When she wore it no man or god could withstand her charms, which was obviously a matter of great concern to the other goddesses during springtime when she reputedly wore it. The necklace also gave support to any army which she favoured on the battlefield.
It was forged by four dwarves (...Dvalin), and, in order to obtain it, she was obliged to spend a night with each of them in turn. Alternatively, King Alberich gave it to her.
It was worn by Thor when he was dressed up as Freya to marry the giant Trym.
Once, the necklace was stolen by Loki. When Freya wakes up she take her wagon, harnesses her cats and goes out to find it. Heimdall helps her search for it and eventually they find the thief, who turns out to be Loki who has transformed himself into a seal. Heimdall turns into a seal as well and starts to fight Loki. After a lengthy battle, Heimdall wins and returns Brisingamen to Freya.
The necklace is referenced in the Anglo-Saxon epic, Beowulf, as Brosingamen, wherein the jewel is brought back to the shining citadel (probably Valhalla which is made of shining armour) by Hama (Heimdall). In this epic, it had eventually fallen into the hands of mortals. It was given to Beowulf by the Danish queen for killing Grendel. Beowulf in his turn gave it to his own queen, Hygd, when he had returned to Götaland.
Alan Garner wrote a children's fantasy novel called The Weirdstone of Brisingamen about an enchanted teardrop pendant necklace.