What might be a consequence if hematite and magnetite became hard to find?

The dissolution of magnetite seems to be related to its transformation to hematite by oxidation of Fe2 + to Fe3+. The transformation of magnetite to hematite occurs along {111} planes, and results in the development of hematite domains along {111} that are parallel to the foliation. The difference in volume created by the transformation of magnetite to hematite and the shear stress acting on the interphase boundaries allow fluids to migrate along these planes.