Oxidation of marcasite and pyrite by iron-oxidizing bacteria and archaea

This study evaluated the oxidation of research-grade marcasite and pyrite in shake flask experiments using iron-oxidizing bacteria and archaea at 22, 45, and 65 °C. Dissolved iron concentration and pH were monitored at intervals. The results showed that marcasite was more reactive than pyrite to both microbiological and chemical oxidation. These results are consistent with established structural and thermodynamic differences between the two minerals, which should make marcasite more reactive to weathering and oxidation.