Ultrafast μLIBS imaging for the multiscale mineralogical characterization of pegmatite rocks

This article presents an innovative application of kHz regime mu LIBS - Laser-Induced Breakdown Spectroscopy for generating detailed compositional maps of geological samples. The method effectively covers large areas (tens of cm2) rapidly while maintaining high lateral resolution (below 20 mu m), producing some of the most extensive LIBS compositional images to date, with a size of 10 million pixels. Employing elemental-based images, we developed a direct methodology for mineral phase identification through mask-creation operations and logical relationships. This approach was successfully applied to reconstruct the mineralogical map of a Li-ore from the west-European Variscan belt, identifying 14 different mineral phases, including economically valuable ones like lepidolite, cassiterite, and columbite-group minerals. Furthermore, based on the reverse normative calculation, the chemical composition of the sample was calculated from the mineral phases previously obtained. The kHz mu LIBS approach marks a significant advancement in elemental and phase imaging, especially pertinent to geological applications, providing comprehensive petro-geochemical insights, essential for a fast geological characterization. This article presents an innovative application of kHz regime mu LIBS - Laser-Induced Breakdown Spectroscopy for generating detailed compositional maps of geological samples.