A thin section of volcanic rock under the microscope, showing the white plagioclase crystals of varying sizes. This rock is from Cerro Tuzgle, a dormant volcano in northwestern Argentina. Credit: The University of Queensland

University of Queensland researchers have shown tiny crystals are a window to activity inside volcanoes and could provide clues to when they might erupt.

Ph.D. candidate Daniela Parra-Encalada from the School of the Environment examined a common white crystal called "plagioclase," found in rocks.

The smallest crystals from Andean volcanoes of different ages, eruptive styles and activity levels had the same chemical signature.…