TEM images of hematite in sample UT97_20. (a) Several hematite crystals lying flat on the lacy carbon film (marked with arrows) and viewed along the crystallographic c axis. (b) Several hematite crystals hanging on the edge of the lacy carbon film. Most of them are viewed approximately perpendicular to the c axis. The crystal marked with an arrow is viewed exactly perpendicular to the c axis. The overlaid circle and ellipse show the cross sections perpendicular to and along the rotation axis, respectively, of the ellipsoid fitted to the X-ray diffraction data.