Oxide Minerals in Soils

Oxide minerals or oxides comprise the oxides, hydroxides, oxyhydroxides, and hydrated oxides of Fe, Mn, Al, Si, and Ti. They commonly occur in soils, particularly those in advanced stages of weathering where they can sometimes account for as much as 50% of the total soil mass. In the discussion to follow, a polyhedral approach will be used to introduce the mineral species and highlight their major differences and similarities (Figure 22.1). For additional structural details, the reader is referred to the literature cited. Thereafter, their occurrence and formation in soils and their influence on soil properties will be discussed, concluding with the major techniques for identifying these minerals in soils.