Fig. 2.

SEM images and drawings showing the morphological features of the spearhead-like magnetite particles. (A and B) SEM images of spearhead-like magnetite particles with pronounced growth steps in the stalk and lower part and well developed crystal faces near the spearhead tip. (C) SEM image of the spearhead-like particle reveals bilateral symmetry. Note abundant conventional magnetofossils surrounding the gigantic spearhead-like particles. (D) Models of idealized crystal habits of the spearhead-like particle shown in A constructed on the basis of the lattice fringe data obtained by HRTEM. These models show the top view (I), lateral view (II), back view (III), and front view (IV).