Oxide Minerals in Soils
Oxide minerals or oxides comprise the oxides, hydroxides, oxyhydroxides, and hydrated oxides of Fe, Mn, Al, Si, and Ti. ¤ey 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 di¦erences and similarities (Figure 22.1). For additional structural details, the reader is referred to the literature cited. ¤ereaer, their occurrence and formation in soils and their in¥uence on soil properties will be discussed, concluding with the major techniques for identifying these minerals in soils.