It's an excellent stone for grounding and protecting, especially in time of stress.
It relieves fear, brings calmness, clears the mind, enhances joy and gives one attentiveness to the moment.
This stone also aids in personal pride and acceptance, it also has a strong link with the earth and the base chakras.
It is easily recognized by its brownish-grey colouring that is produced by aluminium impurities and natural radiation when the crystal is forming.