Studies on the oxidation of magnetite

Magnetite, on dry heating undergoes oxidation with no concomitant change in structure except for cell contraction; the x-ray powder patterns of such oxidized magnetites are similar to that of maghemite. By further oxidation, hematite exsolves as a separate phase and after prolonged heating at 800 degrees C, magnetite is completely oxidized to hematite. The petrogenetic significance of these studies is also discussed.