Pietersite is a type of banded quartz that has formed from brecciated Hawks Eye and Tiger Eye with quartz. The South African mineral is the source of the original find, which is better quality and contains more blue with clearer brecciation. The Chinese mineral is more "brown" and less pretty, hence the variation in price.
Pietersite is also sometimes called "Tempest Stone". This sums its energies up very well! Its combination of tiger eye and hawks eye, which has been broken up and then re-formed with quartz, shows its resilience and the beauty that even chaotic change and upheaval can bring about. This is an excellent choice of stone to support you through times of change, especially if the change is rapid and perhaps bewildering or frightening. It links the blue, indigo and golden-yellow Rays, to bring about balance between the ego-self and the Higher Self, helping us remain grounded and certain of who we truly are, even during times of great change.