[@TheUnknowable] I suppose, I've questioned that myself when playing games like D&D but it kinda makes it all fit because the other elements have energy types in that game (fire for Fire, cold for Water, electricity for Air and acid for Earth), like a lot of earth related things have acid resistance or attacks but whatever.

My point is that crystals shouldn't be an advanced form of Earth because its so simple like stone and stuff. Maybe metal could be the advanced form? Maybe I play D&D too much?