Illuminated Worlds: How Spectroscopy Lights the Way in Earth and Planetary Sciences

T he study of minerals under light, spanning the ultraviolet, visible, infrared (UV-Vis-IR) spectrum, has played an important role in advancing our understanding of terrestrial and extraterrestrial materials. Here, we review light-based spectroscopic techniques across spatial scales in mineralogy and planetary science. Polarized light microscopy helps characterize optical properties, while vibrational and UV-Vis spectroscopies provide insights into mineral structures and compositions. In mineral physics, spectroscopy probes bonding environments, electronic structure, phase transitions, and elastic properties at high pressures and temperatures. In planetary science, UV-Vis-IR techniques from spacecraft and telescopes reveal planetary mineralogy. These methods support the search for habitable environments, planetary evolution studies, and resource identification. Furthermore, technological advances in portability, imaging, and data analysis have improved the precision and scope of mineralogical research.