Pietersite is a silicon dioxide mineral. It has a hexagonal crystal system, a hardness of 7 and is found in South Africa and China. These tumbles, in particular were found in South Africa.
Metaphysically, Pietersite is known as the tempest stone due to it's connection with the storm element. It is said to enhance insight and intuition, increase power of will and aid astral travel and self-transformation. It is highly recommended to those who read tarot or oracle cards as it is believed to make visions sharper and predictions much more exact.