Oxides Minerals

Oxide minerals form a distinctive and essential class of minerals in which oxygen (O²⁻) bonds directly with one or more metal (or semi-metal) cations, producing compounds that often crystallize in igneous environments, during metamorphism or as weathering products at Earth’s surface. These include well-known species such as hematite (Fe₂O₃), magnetite (Fe₃O₄), corundum (Al₂O₃) and chromite (FeCr₂O₄). Because of their relatively simple chemistry compared to silicates and their varied formation settings, oxide minerals provide crucial clues about temperature, oxidation state, fluid history and tectonic processes. They are also directly tied to major ore deposits — for example iron ores, chromium ores and aluminium ores often occur as oxides. In this category you’ll explore how oxide minerals form, how their crystal structures and physical properties reflect those formation conditions, where they occur in the field (or in the subsurface) and why as a geologist, engineer or site-practitioner you should pay attention to them for everything from exploration to material behaviour and geotechnical risk.