Merkaba - Black Tourmaline: a spiritual shield around the holder. Thus, meditating with a Merkaba helps us to connect with our higher self. Black Tourmaline is a very popular stone in metaphysical circles, having many uses. Supportive Black Tourmaline is used for protecting one's energy field against negative vibrations, and also for drawing negative energies away from a person. It can have a calming effect when needed, grounding flighty or scattered energies into the earth.