Answer:
No matter how little or how much you use me, you change me every month.
Not born, but from a Mother's body drawn. I hang until half of me is gone. I sleep in a cave until I grow old. Then valued for my hardened gold.
Whoever makes it, tells it not. Whoever takes it, knows it not. Whoever knows it, wants it not. What is it?
Only one color, but not one size. Stuck at the bottom, yet easily flies. Present in sun, but not in rain. Doing no harm, and feeling no pain.
A dragon's tooth in a mortal's hand, I kill, I maim, I divide the land.
You can always see it, but it's too far away to touch. Mountains rest on it, and at sea it surrounds you. What is it?