Book 27, Question 33
Why do the crystals in a geode point toward the middle?
Crystals grow from wall surfaces outward into any open space.
In a geode, the wall is the starting place, so each crystal sprouts from the wall and points into the empty middle, where it has the most room. Crystals growing next to each other squeeze and compete, which is why some are thin at the base and wider at the tip. It looks like a tiny crystal cave.