Answer:
What an fill a room but takes up no space?
It is sometimes known to have silver linings.
My first half is normally made of stone, my second is crazy, and I taste sweet when complete.
Useful tool for who in darkness dwell. Within you, corrupting like a deadly spell.
Above all things have I been placed Thus have I, a man disgraced. I describe sunlight or lock But after all, I'm just a rock
Brings the sky a lot closer.