Answer:
What starts with a 'T', ends with a 'T', and has T in it?
What can you put in a barrel to make it lighter?
A certain wizard resided in a city made from this gemstone.
My first master has four legs, my second master has two. My first I serve in life, my second I serve in death. Tough I am, yet soft beside. Against ladies cheeks I often reside.
I weaken all men for hours each day. I show you strange visions while you are away. I take you by night, by day take you back. None suffer to have me, but do from my lack.
The strangest creature you'll ever find: Two eyes in front and many many more behind.