Laboratory experiments were conducted to compare iron precipitation under completely ferruginous conditions with solutions that contain a low amount of oxidized iron, which can be seen as a proxy for iron oxidation in the environment. and Some XRD files are from a copper source (Cu_XRD) and others are from a cobalt source (Co_XRD).
Isaac L. Hinz, Christine Nims, Samantha Theuer, Alexis S. Templeton, Jena E. Johnson; Ferric iron triggers greenalite formation in simulated Archean seawater. Geology 2021; doi: https://doi.org/10.1130/G48495.1