A one‐pot synthetic procedure yields the octanuclear FeIII complex [Fe8(µ4‐O)4(µ‐4‐tBu‐pz)12Cl4] (2). The molecular structure of 2 resembles the building units of iron‐containing minerals like magnetite, ferrihydrite and maghemite. Based on mechanistic investigation we propose that in presence of Et3N, iron(III) pyrazolates are reduced to iron(II) pyrazolates, which then activate dioxygen to form 2. Complex 2 exhibits unique spectroscopic and electrochemical properties relative to those of the previously reported Fe8 clusters based on pyrazolate ligands. Furthermore, 2 can oxidize water to hydrogen peroxide, thereby mimicking the water splitting process taking place at the surface of magnetite. Compound 2 therefore acts as both structural and functional models of iron‐containing minerals.