What contrast exists between the Martian crustal inventory and the potential iron state in the core?

Crust is overwhelmingly oxidized while the core may still hold substantial metallic iron

When conceptualizing the total iron budget on Mars, a clear distinction arises between the crust and the core. The crustal inventory is characterized as being overwhelmingly oxidized, evidenced by the surface being covered in stable, non-magnetic hematite ($ ext{Fe}_2 ext{O}_3$). This suggests that the oxidizing environment successfully converted nearly all available surface iron. However, the core, despite no longer maintaining a global magnetic field, may still contain substantial deposits of metallic iron. This implies that the intense oxidation processes were largely confined to the crustal layers, leaving the deeper, less exposed metallic iron largely unaltered chemically.