Bauxite forms by the weathering of aluminum rich and silica poor rocks in hot, humid, climates, at places with good drainage. Under the proper conditions, weathering disintegrates the aluminium silicate minerals, and dissolves and removes the silica, creating bauxite. The mined US bauxite deposits have all been in the southeastern United States.
About 90 percent of American mined bauxitee from deposits in central Arkansas. The Arkansa