Answer:
I am cracked by Indiana Jones.
It's in your hand though you can not feel it. Only you and time can reveal it.
I think you live beneath a roof that is upheld by me; I think you seldom walk abroad but my fair form you see; I close you in on every side you very dwelling pave and probably I'll go with you At last into the grave.
I can be long or short. I can be grown or bought. I can be painted or left bare. My tip can be round or square. (one word)
I am like thunder in your cranium
Give it food and it will live, give it water and it will die.