Answer:
I am a precious stone as clear as diamond. Seek me out while the sun's near the horizon. Though you can walk on water with my power try to keep me and I'll vanish in an hour.
I am just two and two. I am hot. I am cold. I am the parent of numbers that cannot be told. I am a gift beyond measure, a matter of course. What am I?
Marking mortal privation when firmly in place. An enduring summation inscribed in my face.
You write on me and secrets I can keep. In places never seen. I spin like a top. Though stiff as a board I'm often described like a mop.
I'm blue at day and black at night. I do contain some creatures born and died. What am I?
What is always coming but never arrives?