Black Tourmaline is also called Schorl. It is a complex aluminum borosilicate, has a hexagonal crystal system and a hardness of 7 - 7.5.
Metaphysically, it is said to offer psychic protection for those that work or live in challenging environments, keeping one's auric field clear of imbalance even when destructive energies are present. Another use for black Tourmaline is etheric purification. Holding, carrying, meditating or sleeping with this stone is said to provide one with a refreshing cleanse for their auric field and etheric body. Black Tourmaline is also believed to ease anxiety, anger, self-judgement and feelings of unworthiness.
The protective energies of black Tourmaline are said to be enhanced by combining it with either smokey quartz, amethyst, jet, obsidian or andradite garnet.