The black Obsidian Stone is a powerful cleanser of psychic smog created within your aura, and is a strong psychic protection stone. It has powerful metaphysical properties that will shield you against negativity, and the energy of these stones may stimulate the gift of prophecy. This black stone is excellent to assist you to release disharmony that has built up in your day to day life and during work on yourself, including resentment of others, fear and anger. In summary it:

Eliminates ones negative energies
Cleanses the auric field
Good for grounding
Cleanses negative emotional patterns
Removes blockages in the meridian system
Victoria Beckham has been seen with one of these and it is reported that she has given each of her staff one to promote positive thinking