Answer:
What looks back but cannot see?
Tall in the morning, short at noon, gone at night. But I'll be back soon.
Break it and it is better, immediately set and harder to break again
I am two-faced but bear only one. I have no legs but travel widely. Men spill much blood over me. Kings leave their imprint on me. I have greatest power when given away, yet lust for me keeps me locked away.
Round as an apple, deep as a cup, and all the kings' horses can't fill it up. What is it?
I’m grown from darkness but shine with a pale light. Very round I am and always a lady's delight.