Pyromagnetism

Pyromagnetism is the study of the magnetic properties of heated materials and deposits. In archaeomagnetic terms Work ranges from the identification of the heat treatment of materials to improve their qualities, such as the baking of silcrete to make specific stone tool technologies (seeĀ Brown et al 2009 Science) or the reconstruction of the thermal history of hearths, fireplaces and burnt rocks (see Herries, 2009).

South African before and after heat treatment where a dramatic colour change occurs from yellow goethite to red haematite
South African silcrete before and after heat treatment where a dramatic colour change occurs from yellow goethite to red haematite (credit, Kyle Brown)