Walnut jasper is a form of picture jasper. Jasper is an opaque, impure variety of silica in the form of chalcedony or microcrystalline chert. Generally it forms near volcanic activity and the circulation of hot water is thought to be required for its formation. The patterns in picture jasper are caused by flow or deposits unique to their region of origin.
Picture Jasper is thought to help enliven and awaken creativity and initiative. It is said to encourage visualization and business pursuits. It is also said to help alleviate fear.