ROLE OF STRUCTURAL IMPURITIES IN POLYMORPHIC TRANSFORMATIONS IN QUARTZ

Abstract

Ultrapure quartz samples from deposits of the Netherpolar Urals were studied by the EPR technique. Almost all samples contain an impurity of high-temperature beta-quartz, which is not related to the thermal conditions of mineral formation. It is suggested that the beta-phase formation is a result of the low concentration of At impurity in quartz. It is shown that the high-temperature phase is preserved in natural samples due to an admixture of structural Ge generally owing to diffusion.