black tourmaline is a very versatile gemstone, it's also black because it consists of all the colors of the rainbow! 
because tourmaline has of all the colors it works on the balancing and grounding of all the chakras
black tourmaline’s male energy has the ability to block negative energy, in this sense it becomes as a protector
the feminine energy of tourmaline is a receiver to positive energy
it also has the ability to turn dense energy (not necessarily negative energy) into light