Bauxite

This rock was formed by the weathering of nepheline syenite under tropical conditions, a process called laterization.  It is a type of lithified soil which is relatively low in silica and high in aluminum.  Bauxite was discovered in Arkansas before 1900 and was a major source of ore for aluminum metal for some 90 years in Saline and Pulaski Counties.  There are many uses for processed bauxite, aside from metal, including abrasives, cement, refractories, and chemicals.  Aluminum compounds are essential ingredients in many common household items, including deodorants, antacids, and paper.