Nanolite cargo evolution in trachybasaltic glass comparing magnetite and augite

This study investigates the relationship between crystallization behavior, magnetic and mechanical properties, and crack formation in a trachybasaltic glass using differential scanning calorimetry (DSC), Raman spectroscopy, X-ray powder diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), and Vickers indentation tests. Various thermal treatments modify the crystalline cargo (i.e., crystal content), affecting hardness, crack resistance, and magnetism. Single-step annealing at 850 °C rapidly generates nanocrystals, enhancing mechanical strength and inducing ferromagnetic behavior. In contrast, a two-step annealing process (750 °C → 850 °C) promotes gradual magnetite formation, increasing hardness and reducing crack formation while maintaining a predominantly paramagnetic response. These findings suggest that irregular volcanic heating patterns may drive natural crystallization, influencing elastic energy storage and altering failure dynamics.