Best to keep around every corner of your house or by your front door or any door! to remove negative energy to whoever enters your space.
Black Tourmaline- One of the best grounding stone! Black Tourmaline id there to provide a shield of protection around you removing and blocking out all the negative energy and tendencies, that's why it's good to have a piece of tourmaline under the driver's seat. Also it absorbs electromagnetic radiation to keep you protected from all the electronics nowadays.