Our recent observation on the morphology of natural and synthetic quartz crystals is reviewed. The basal face in natural quartz crystal from Four Peaks(Arizona), Sichuan (China) and Nose (Osaka), the Japanese twin from Narushima (Nagasaki) and the abacus ball-type crystals from Dal’negorsk (Russia) are mentioned. On the synthetic quartz crystals, it is stressed that mixed dislocations play a different role in the growth mechanism between the smooth interfaces (r, z, m) and the rough interface (Z). Mixed dislocations form spiral growth hillocks (r, z, m), and show two-dimensional morphological instability to form cobble II (Z). Adsorption of Al impurity along steps on the vicinal face of growth hillocks on the m face controls the macro-morphology (enlargement of the S face).
抄録全体を表示