Answer:
It is a form of plastic money.
This became a fashion statement in the garden of Eden.
I'm a god. I'm a planet. I measure heat.
Sometimes it's silver but also gold. Printed on paper it's a treasure to hold. What is it?
The day is their night and the night is their day, when I shout and they shout back I run away.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?