Gibbsite, a major source of alumina, occurs in the northern and inner sections of the Piedmont Province of Alabama in soils and saprolite derived from amphibolites, granites, feldspathic hornblende gneiss, and other gneissic rocks. The major occurrences of gibbsite are in areas underlain by hornblende gneiss in Chambers and Randolph Counties. This region provides the proper physiographic and mineralogical setting for large areas containing up to 25 percent saprolitic gibbsite. These areas provide potential sources of alumina that could be used to meet the U.S. future needs. Narrow zones and pockets rich in gibbsite also occur in soil and saprolite derived from areally restricted feldspar-rich zones of narrow linear amphibolites in the inner piedmont and feldsphatic zones in various granites distributed throughout the Piedmont.