Crystal Grids by Medium Paul
Crystal grids can ground and balance the energy in rooms or an entire space/house.
Depending on the goals, for example if a person with no earth sign planets in their astrology birth chart has grounding issues (no earth) stones would be placed on the 4 sides of each room to ground and stabilize.
Sometimes EMF radiation needs to be neutralized and specific stones will resolve and neutralize the EMF radiation.
Crystal grids vary in composition because the goals and objectives being met vary.