Answer:
I can be moved. I can be rolled. But nothing will I hold. I'm red and I'm blue, and I can be other colors too. Having no head, though similar in shape. I have no eyes - yet move all over the place.
A certain wizard resided in a city made from this gemstone.
Through its wounds, water does run. It once held many but now has none. What is it?
As a whole, I am both safe and secure. Behead me, I become a place of meeting. Behead me again, I am the partner of ready. Restore me, I become the domain of beasts.
What weaves webs as they grow?
What never gets any wetter no matter how hard it rains?