抄録
Cloven surface of sodium chloride crystals, both rock salt and artificial, was observed by means of X-ray diffraction microscopy (Berg-Barrett method). X-ray patterns by (420) or (440) reflection reveal the sub-grain structure very clearly. In artificial crystals, the dimen-sion of the sub-grains is 0.5_??_5mm and the maximum difference in orientation of sub-grains is 50'. In some specimens there are sub-grains consisting of micro-domains. The size of these micro-domains are several-hundredth mm in diameter. The difference in orientation, if any, among the micro-domains was not detectable within the resolving power of the camera used (2'). In natural rock salt crystals, the dimension of sub-grains and the orientation difference among them are of the same order as in the case of artificial crystals. The micro-domains are not found in natural crystals.
