Supergene (or weathering) processes, occurring near the Earth’s surface, are the geochemical phenomena that describe the alteration of primary minerals in contact with water and atmospheric gases to form more thermodynamically stable secondary minerals. Supergene alteration involves a suite of chemical reactions, including oxidation, hydration, dissolution and precipitation, predominantly influenced by climatic conditions, lithology, topography and hydrology. These reactions result in the decomposition of primary minerals, the release of metals into solution and their transport and reprecipitation as secondary minerals, governed by factors such as redox potential, pH, complexation and adsorption-desorption, driven by factors such as temperature, precipitation, organic matter input and microbial activity. Silicate weathering plays a crucial role in regulating atmospheric CO2 concentrations by its consumption during mineral dissolution. Selective leaching and preferential enrichment mechanisms lead to the concentration of economically valuable elements and minerals, including copper, nickel, cobalt, aluminium, iron, gold and kaolinite, to form supergene ore deposits. An understating of these processes has implications for ore genesis, exploration targeting strategies, mining and metallurgy and environmental management. Due to the importance of oxygen during weathering, the maximum age of such products is about 2.2 billion years, i.e. after the ‘great oxidation event’. Climate has and continues to play an important role in the development of supergene mineral deposits as it exerts control over precipitation, evaporation and temperature as well as concentration levels of reactive gases in the atmosphere.