Abstract
The author have investigated the crystallinity of galena by means of x-ray spectrometer. It was found that galena showed structural plasticity on heating and grinding. The main results obtained were as follows:
(1) Recrystallization of galena on gentle heating was clearly observed from diffraction peak profile, and the crystallinity was increased in increasing with heating temperature.
(2) Disordered galena because of soluble minor impurities showed lattice expansion on heating.
(3) Crystallinity was destroyed by grinding and was recovered on heating again, and structural plasticity of galena was observed.
