According to OHKAWA et al. (2007) coarse-grained maghemite (i.e. when produced by magnetite alteration) is quite unstable. The presented rounded aggregate, according to PXRD analysis, consists of goethite and hematite formed in cost of maghemite. Diffraction pattern shows also some amounts of maghemite. Close to its reflections, magnetite ones are seen, too. Field of view is 3 mm.
OHKAWA M., MIHAYARA M., OHTA E., HOSHINO K., 2007: Silicon-substituted magnetite accompanying iron oxides and hydroxides from the Kumano mine, Yamaguchi Prefecture, Japan: Reexamination of the so-called maghemite (γ-Fe2O3).