Laterite is a soil type and rock formation that is rich in iron and aluminum oxides, formed through the intensive and prolonged weathering of underlying parent rock in tropical and subtropical regions. It is one of the most significant geological materials in both bauxite and gold mining industries. In bauxite mining, laterite serves as the primary ore body, as it represents the deeply weathered regolith within which gibbsite, boehmite, and diaspore — the key aluminum-bearing minerals — are concentrated. The lateritization process involves the leaching of silica and other soluble components by rainwater over millions of years, leaving behind a residual enrichment of aluminum hydroxides and iron oxides.
In gold mining, laterite profiles can host secondary gold deposits formed when primary gold-bearing rocks undergo deep weathering. Gold particles originally disseminated in sulfide-bearing primary ore may be redistributed and concentrated within the laterite horizon. The color of laterite typically ranges from yellow to red to dark brown, depending on the degree of iron oxide content and hydration state.
Laterite profiles are generally stratified into distinct horizons: a surface zone, a mottled clay zone, a ferruginous duricrust (hardcap), a pisolitic zone, and the bauxite-rich horizon above a transitional saprolite layer. Mining engineers and geologists must carefully understand the vertical and lateral distribution of these horizons to optimize extraction strategies and plant feed quality. The softness and friable nature of laterite relative to hard rock deposits makes it amenable to simple excavation using scrapers and front-end loaders, significantly reducing mining costs in bauxite operations.