ABSTRACT
Quartz is one of the most abundant minerals on the surface of the earth, paramagnetic defects in which have been the subject of scientiic interest for a long time. It was found that paramagnetic defects in quartz make “chemical reactions” in its crystal lattice so that the formation of the E 1′ center (unpaired electron at an oxygen vacancy) is controlled by the concentration of aluminum impurity. Impurity centers of hole type and electron type seem also to react each other which aff ects the decay of the centers on heating. Formation of the oxygen vacancies in quartz is one of the topics further to be investigated where temperature dependence of formation eficiency will be a key feature to discuss the issue. Dating of natural quartz based on the measurement by ESR (electron
spin resonance) of natural accumulated dose is one of the important applications, which have been applied to determine the ages of fault movements, volcanic eruption, heating of implements, and sedimentation in river. The E1′ center in quartz was also found to be a useful proxy in investigating material transport on the surface of the earth, based on which the environmental changes in the past are discussed.
