Mineralogical Identification of Traces of Life

Many organisms impact mineral nucleation and growth. This results in the formation of biominerals with chemical, structural and textural properties providing clues to their biogenicity. However, ageing modifies these properties to some extent. Moreover, some abiotic processes form minerals with similar properties. Therefore, decoding traces of life in minerals requires caution, and one prerequisite is a reliable estimation of the geochemical conditions under which a biomineral formed. Here we discuss several examples of biominerals which illustrate these different ideas.