You have resistance to cold damage while wearing this necklace. To those of Giants blood a poem can be heard from within this necklace. 

From Ymir’s flesh the earth was created,
And from his sweat and blood the sea,
Mountains from bone,
Trees from hair,
And from his skull the sky.

And from his eyebrows the blithe gods made
Midgard, home of the sons of men
And from his brains
They sculpted the grim clouds.

Notes: Resistance: Cold, Resistance: Fire, by a Paladin or Giant