Answer:
Fred and Wilma's child, named after a stone.
What kind of room has no doors or windows?
What is yours but only used by others?
Shorter than my four siblings, but easily the strongest, Sometimes I wear a funny hat.
Written on with words of white, Has the color of the night, Is the teacher's best delight, And a student's daily fright
If itβs information you seek, come and see me. If itβs pairs of letters you need, I have consecutively three. What am I?