Answer:
I have rivers without water. Forests without trees. Mountains without rocks. Towns without houses.
I cost no money to use, or conscious effort to take part of. And as far as you can see, there is nothing to me. But without me, you are dead.
What looks back but cannot see?
What is often returned but is never borrowed?
With sharp edged wit and pointed poise. It can settle disputes without making a noise.
Iām grown from darkness but shine with a pale light. Very round I am and always a lady's delight.