The Mössbauer spectra of prasiolite and amethyst crystals from Poland

Abstract

Mössbauer spectroscopy of green (prasiolite) and violet (amethyst) quartz crystals from the Sudety Mountains (Poland) has shown that neither Fe 2+ nor Fe 4+ ions are present in them. Only Fe 3+ ions have been identified and only in interstitial positions in channels parallel or perpendicular to the c-axis. The valence of Fe 3+ ions did not change as a result of irradiation or annealing. Instead, we believe that the Fe 3+ ions move within channels or between them.