Answer:
A certain wizard resided in a city made from this gemstone.
Some live in me, some live on. And some shave me to stride upon. I rarely leave my native land. Until my death I always stand. High and low I may be found. Both above and below ground.
It cannot be seen, it weighs nothing, but when put into a barrel, it makes it lighter.
This is in a realm of true and in a realm false, but you experience me as you turn and toss.
A house full, a yard full, a chimney full, no one can get a spoonful.
What do angels sing in the shower?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?