Answer:
Marking mortal privation when firmly in place. An enduring summation inscribed in my face.
I have four fingers and a thumb, but I'm not living. What am I?
I help you carry your books.
I climb higher as I get hotter. I can never escape from my crystal cage.
I can climb mountains, cross streams, handle hundreds of feet each day, yet I never move. What am I?
Black we are and much admired. Many seek us if they are tired. We tire the horse, and comfort man, and turn White when we've fulfilled your plan.