(a) HRTEM image of a hematite crystal viewed perpendicular to the c axis. (b) Fast Fourier transform of (a). The marked spots have the observed d spacings 2.29 and 2.53 Å, corresponding to the 0006 and 120 reflections of hematite, respectively. (c) Close up of the area marked with the white rectangle in (a). (d) Simulated HRTEM image of hematite.