black tourmaline is a powerful protection stone. this crystal is studied by scientists because it has physical properties like piezoelectricity (meaning it can store an electrical charge) and pyroelectricity (meaning it can generate electricity when heated). it is a great detoxing and grounding stone. it works with the root chakra.
this listing is for (1) black tourmaline sphere of your choice using the numbers listed. the numbers for each crystal are shown on the second picture onward.