Answer:
I am not a toy though many use me for pleasure. I have a butt but I cannot poo.
I am the book one can never finish reading
I break down buildings, I crumble mountains but you can't see me. What am I?
I am an insect and the first part of my name is the name of another insect. What am I?
I hold two meanings. With one I may be broken with the other I hold on.
It flows out of the soil, It burns you if it boils, And holds us in its coils, More valuable than gold, As black as it is old.