Pietersite is dark blue-grey breccia aggregate made up mainly of hawk's eye and tigereye. It is a variety of chalcedony (itself a variety of quartz) with embedded fibers of amphibole minerals in varying degrees of alteration.  pietersite has been used for many years as a great supporter of the nervous system, allowing those around it to experience decreased light-headedness, dizziness, or headaches. It is also used to heal dull eyesight or eye infections