Crack crystal is actually rock crystal subjected to pressure to give it a cracked aesthetic. So actually a transparent quartz originally. The lithotherapy books shelter rock crystal and all clear quartz with multiple properties depending on the origin and shape of the stone. The bottom line is that rock crystal is a stone of power, clarity and balance. It is also observed for this stone that it improves memory, develops perception and allows one to have a clear mind. It stimulates energy flows and therefore the nerves and the brain. In fact it is recommended for all organs requiring an energy contribution during pathologies encountered, a naturopath will be able to indicate the shape of the stone which is appropriate and how to wear it. Rock crystal is suitable for all astrological signs in fact it is suitable for everyone at some point in their life.