This is the process of the oxidation of iron sulfide (FeS2) to form iron hydroxide (Fe(OH)2) through a series of reactions involving the formation of different iron oxides.

FeS2 is oxidized to form Fe2O3 (iron (III) oxide) and sulfur dioxide gas (SO2).Fe2O3 is further reduced to form Fe3O4 (iron (II,III) oxide).Fe3O4 is reduced to form FeO (iron (II) oxide).FeO is further reduced to form elemental iron (Fe).Finally, Fe reacts with water to form iron hydroxide (Fe(OH)2).

This series of reactions involves the transfer of oxygen atoms from the sulfide mineral to form different iron oxides until the final product of iron hydroxide is formed.