Answer:
A certain wizard resided in a city made from this gemstone.
What can you put in a barrel to make it lighter?
I scribble forms of the finest letter, And repel elements of the harshest weather. I am an arrow-aimer and a dust-breaker.
Hold the tail, while I fish for you.
Everyone has it and no one can lose it, what is it?
Special abilities and brightly colored underwear are all you need to be one of these.