Sweeping investigations on grown-in Al-Li+ and Al-OHcenters in natural crystalline quartz

摘要

Near-infrared absorption in the region of 3100-3700cm-1 is used to study a variety of optically clear samples ofnatural quartz crystals. The crystals are hydrogen-rich andhydrogen-lean with approximately the same or varying aluminiumconcentration. The alkali concentration in hydrogen-rich samples is muchhigher than that in hydrogen-lean samples. The very narrow variation inthe strength of centers in all small samples suggests that Al-OH- centers in natural quartz become stable only after a certainmaximum Al-Li+ concentration. This concentration appears tobe independent of the origin of the growth and reflects a characteristicfeature of the growth mechanism of natural quartz crystals