Answer:
I have a ring but no fingers. I used to stay still all the time but nowadays I follow you around.
I fill a room but take no space.
The more of me there is the less you see.
I transfer oxygen from the atmosphere to your blood
Lighter than what I am made of, more of me is hidden than is seen. What am I?
Born of earth, but with none of its strength. Molded by flame, but with none of its power. Shaped