Abstract
Development of hydrothermal growth of quartz crystals in Japan is reviewed. Close relationship between physical properties of quartz, its Q-value estimated by infrared absorption method and electrical characteristics is observed. The fact that inclusions, dislocations and impurites are deeply related to the quality of quartz crystals is also shown. Quartz crystals grown in NaCl, KCl solutions and pure water are proved to be practically equivalent to natural quartz.
