Geodes are really useful to me. Their shape naturally makes them good receptacles and absorbers. Pain, sadness, negativity. Before I cut circle or enter a circle, I meditate with a geode and fill it with all my cares and worries and all that baggage that I don’t need while working.
Have a headache? Lay back and place a geode on your forehead and just let it do the work. It’ll absorb the pain and then you can just put it in some salt water or in a window sill to cleanse it. :)