Black Tourmaline will ground you quite quickly, so it is highly beneficial to keep a piece of this stone on you.
If you do a lot of spiritual work, or have strong psychic abilities and you use these abilities quite a lot, you may become ungrounded.
This is one of the stones that I always keep in my pocket or wear as jewelry, along with a few others. It is helpful both for grounding and for protection from beings from the lower realms.
If you acquire a small cloth bag, and many crystal shops sell them, you can put your crystals in your pocket easily each day, just so you don’t lose them.
I know that there are stones that send back the negative energy, but this stone will not do that unless it has inclusions of mica in it, see the silvery inclusion in the stone on the left.