The sexquioxide classification of laterite refers to the classification of laterite soils based on their content of sesquioxides, which are oxides with three atoms of oxygen and two metal atoms. Laterite is a soil and rock type that is rich in iron and aluminum, and is commonly found in hot and wet tropical areas. It forms through the intensive and prolonged weathering of the underlying parent rock, usually under conditions of high temperatures and heavy rainfall with alternating wet and dry periods. The sexquioxide classification of laterite is used to describe the composition of these soils, which can vary depending on factors such as the parent rock, the degree of weathering, and the local climate.

• https://link.springer.com/chapter/10.1007/978-3-319-09057-3_388
• https://unesdoc.unesco.org/ark:/48223/pf0000071101