I is for Idunna.

Idunna was a youthful and innocent goddess in Asgard home of the Norse Gods. She was the caretaker of the golden apples that maintained the gods' youth and health. The giant, Thiazi kidnaps her in order to make life difficult for the gods but she is rescued by Loki in Freya's Falcon cloak. Thiazi is killed by the gods as he tries to take her back and his daughter, Skadi wins the hand of Njord as payment for his death.

The son's of Ivaldi are the makers of the treasures of the gods;
The golden hair of Sif which was made of gold and grew instantly to her head (to replace her real hair which Loki cut off as a prank).
Skidbladnir a marvelous ship for Freyr whose sails fill instantly with wind and when it is not in use could fit into his pocket.
Gungnir A spear for Odin which never misses its mark.

Note* My theme for the A-Z challenge is Norse Mythology. Last year I did a Waldorf alphabet book which can still be found on this website under April 2011 postings.