Answer:
In the night a mountain, in the morning a meadow.
The ones who see it may go blind, Contracting the fool's madness. You have to dig to find it, Crush big stones or mine it. Wash dirt clumps in a pan and wait for it to settle, A shiny, precious metal.
I am free for the taking. Through all of your life, though given but once at birth. I am less than nothing in weight, but will fell the strongest of you if held.
What building has the most stories?
My second is performed by my first, and it is thought a thief by the marks of my whole might be caught.
What covers its face with its hands, speaks no language, yet most known what it's saying?