Anomalous thermal stability of the [GeO4]- Electron Paramagnetic Resonance signal and the 110 °C Thermally Stimulated Luminescence peak in natural and synthetic quartz

In this work we studied the thermal stability of the 110 °C TSL peak of quartz in both natural and synthetic samples. We compared it with the thermal stability of the [GeO4]- paramagnetic signal with EPR. Our findings show that both these signals decay at the same rate, however, the rate is significantly different between samples. In particular, a couple of samples, a pegmatitic one and a fired synthetic one, showed a drastically increased decay time of both the TSL peak and the EPR signal well beyond the expected experimental fluctuations. The decay time of these two samples differs by almost by a factor two with respect to the average value of all the other samples.