Palaeomagnetic and mineral magnetic data are used in a wide variety of Earth science disciplines. Reconstructions of the direction and intensity of the Earth's geomagnetic field can be produced from studies of igneous rocks, sediments and ceramic artifacts. These reconstructions can be used to (i) correlate and date geological archives and (ii) help us understand how the geomagnetic field is generated. In addition, the concentration and type of magnetic minerals found in nature can be diagnostic of the environmental conditions that prevailed at the time of their formation, with applicability to palaeoclimatology and biogeochemistry. The combination of palaeomagnetism and mineral (rock) magnetism has become known as Environmental Magnetism.