I'm looking for a movie I watched as a kid but I don't remember much about it. I remember that the main character was a boy who had a pet dog. He is at some point near the beginning chasing little green things that glow while on a stone staircase. When he picks them up I think it was an egg carton like container he puts them in. He goes into a cave and there are crystals that make his head appear to be different shapes when he looks through them. That's all I remember. I believe it must be from the 70s or 80s. Any help would be greatly appreciated.