Basalt is an igneous rock that forms from the relatively rapid solidification of basaltic lavas and is one of the most common types of rock in the world. The rocks themselves have the basic elements for life including carbon, phosphorous and nitrogen, only requiring water to complete the formula. It is high in silicates, iron, and magnesium. It is high in sulphur, an active ingredient which not only helps the body to resist bacteria but actually destroys it. It is a strong, abrasive exfoliant and works exceptionally well on hard, calloused skin like the bottom of the feet.