Black tourmaline is one of the best negative energy sucker stones there are. It helps with negative energy in a space as well as on a person. it is said to cleanse, purify, and transform negative energy into a higher vibration. it balances the chakras and help energetically protect an individuals energy field. They must be cleansed, just like most protective/cleansing stones, but something as simple as energetically intending for them to release whilst running under water is one of the simplest ways to reset them.
We have a few different grades of torumaline, and pictured here is the B Grade example, followed by the A+ or AA Grade pieces.