Answer:
Describes universities like Harvard and can be poisonous.
A precious stone, as clear as diamond. Seek it out while the sun's near the horizon. Though you can walk on water with its power, try to keep it, and it'll vanish in an hour.
When does Christmas come before Thanksgiving?
It's equally comfortable in an orchestra and a geometry textbook. What is it?
Bury deep, Pile on stones, My mind will always Dig up them bones
You use it between your head and your toes, the more it works the thinner it grows.