Laterite

Laterite is a reddish weathering product of basalt due to the presence of iron oxide. However, not all Laterites are enriched in iron and sometimes they are not even reddish. Some Lateritic rocks (Bauxite) are mined because of their high aluminum content. Iron-rich variety is mostly used as a construction stone & as a binder in cement plants because they become hard like iron when exposed to air.