Answer:
I am as hard as metal, yet as flimsy as glass. I shine like a star, yet I am only a rock. What am I?
What is the edge of earth and bread?
I make you weak at the worst of all times. I keep you safe, I keep you fine. I make your hands sweat and your heart grow cold. I visit the weak, but seldom the bold. What am I?
I am the key that is the hardest to turn
I move without wings, between silken strings. I leave as you find my substance behind. What am I?
The profession of Jimi Hendrix and Eric Clapton