Submicroscopic Topography of Oxidized Surface of Stibnite and Etched Surface of Zincblende

Submicroscopic topographies of oxidized stibnite and of etched zincblende were examined by electron microscopes. Crystallites of antimony oxide formed on stibnite have a roof-like shape bounded by two well-developed and four less developed {111} faces. This is in agreement with the conclusion drawn previously from electron diffraction study (Miyake, Sc. Pap. I. P. C. R. 34 (1938), 565). The direct observation by electron microscope gives some further information on the growth of the oxide. Zincblende surfaces etched by hydrochloric acid has a shape which is slightly different from the negative triakis tetrahedron inferred from electron diffraction study (Uyeda et al., Proc. Phys. -Math. Soc. Japan 24 (1941) 1049). In the diffraction patterns from this surface, structures of reflexion spots finer than those previously reported were observed and analysed by the theory of the dynamical refraction effect.