Explosive volcanic eruptions, which can send gas and ash kilometers into the sky, are among the most destructive geological events. The viscosity of the magma also influences its violence: the denser it is, the easier it traps gasses within it, until pressure builds up and a rapid explosion happens. A recent international study conducted by Pedro Valdivia Muñoz of the Bayerisches Geoinstitut in Germany and coordinated by Danilo Di Genova of the CNR-Issmc in Rome discovered a nanometric-scale mechanism that can immediately raise magma viscosity by up to 30 times. A finding that potentially transforms our knowledge of eruptive dynamics. The research, which was published in Communications Earth & Environment, has enabled the first-ever real-time observation of the formation of microscopic crystals -  known as "nanoliths," which are composed of iron oxide and titanium - within an andesitic magma, a type of magma that is characteristic of numerous explosive volcanoes. These nanocrystals, which are less than a thousandth of a hair's diameter, significantly modify the structure of the magma, rendering it significantly more viscous and, as a result, more hazardous. This discovery was made possible by using modern imaging techniques and combining high-temperature tests with comprehensive nanoscopic investigations. In addition to providing fresh insights into volcano risk assessment, the research opens up new possibilities in the field of advanced materials, such as glass-ceramics, where nanometer-scale crystallization management is critical. Therefore, even the most minute transformations within the Earth can have significant repercussions, as a minor alteration in the magma's composition can have substantial repercussions.