Pietersit cabochon drilled top quality 36.9g, Namibia

The very essence, power and beauty of a summer storm is literally enshrined in the beautiful pietersite stone, for in pietersite you see brilliant flashes of golden light amid swirling clouds in the deepest blue. Pietersit is also known as the Lightning Stone or the Storm Stone because it is charged with a powerful energy that is almost palpable.
Pietersit is a variety of quartz whose chemical composition is similar to that of the generally well-known tiger's eye or jasper. Compared to them, however, pietersite is often characterized by an even stronger "cat's eye" effect, which arises due to the fibrous structure in the quartz, as in cat's eye, or the inclusion of another stone in the cavities in the stone, such as in chrysoberyl.