I am a white feather on the back of the night. I have many phases, but I’m never out of sight. What am I?

I bite the ocean floor, but never chew, clinging to earth beneath the blue. Though born of iron, I sleep in sand, holding giants with one hand.

I come from high above, dark and with a magnet quality. I am said to have changed the world dramatically.

I shimmer where your longing leads, A promise born of burning needs. I paint you gifts you cannot claim, A distant pool without a name. You chase me, though I never stay, I live in heat, then fade away.

I have a bark but cannot bite, I am very small and light, Broken off by the wind, you’ll see, I'm a tiny piece of a tree