Both initial concentrations of Fe(II) and monovalent cations jointly determine the formation of biogenic iron hydroxysulfate precipitates in acidic sulfate-rich environments

► Study on the formation of precipitates in acidic, sulfate-rich environments. ► Relationships between mineralogy and initial Fe(II) conc. and Fe/K molar ratios. ► Both the initial Fe(II) and K+ determine the type of iron precipitates.