Abstract– Physical properties of multidomain magnetite-bearing porous pellets shocked up to 45 GPa were measured. The results show general magnetic softening as a result of shock. However, a relative magnetic hardening trend and slight magnetic susceptibility decrease is observed with increasing pressure among shocked samples. Initially, the shock also seems to cause a slight decrease in porosity, but at higher shock pressures macroscopic porosity increases progressively in our pellets. The microscopic porosity remains almost unchanged. Since our samples have distinctly higher initial porosity compared with samples used in previous studies, our results may be representative for impacts into highly porous magnetite-bearing sedimentary or volcanic rocks and are relevant to impacts into such target rocks on Earth and Mars.