Scanning electron microscope observation of dislocations in olivine

Dislocations in olivine decorated by oxidation in air were observed with a scanning electron microscope (SEM) using a backscattered electron image (BEI). The decorated dislocations (and grain boundaries) were found to give clear bright images in this mode, indicating an increase of mean atomic number near the dislocation cores (and grain boundaries). This method of dislocation observation has a resolution of ca. 0.1 μm, about an order of magnitude better than optical microscopic observation, and is particularly useful in the study of the overall dislocation distribution of naturally and experimentally deformed olivines with relatively high dislocation densities.