Cathodoluminescence image of Zircon (IMAGE) Université de Genève Caption Cathodoluminescence image of Zircon crystals from Nevado de Toluca volcano in Mexico Credit UNIGE/WEBER Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.