Halogen (F, Cl, Br, I) compositions of minerals and whole-rocks from cryolite-bearing granitic systems

This dataset provides a comprehensive, multi-scale geochemical and mineralogical archive from the Ririwai cryolite-bearing granitic complex, systematically documenting halogen (F, Cl, Br, I) behavior and rare-metal enrichment signatures during magmatic-hydrothermal evolution. The data scope integrates whole-rock major and trace element geochemistry with high-precision volatile concentrations. At the crystal scale, the dataset captures in-situ major and trace element compositions of key rock-forming and accessory phases, specifically arfvedsonite, biotite, cryolite, gagarinite-(Y), pyrochlore, and columbite, complemented by quantitative F and Nb partitioning trends across the mineral assembly. Late-stage fluid-melt evolution records are tightly constrained by major and minor element chemistry profiles of fluoride melt inclusions hosted within arfvedsonite grains. Furthermore, the dataset integrates quantitative petrographic data through mineral modal proportions and numerical mass-balance models evaluating the elemental budgeting of F, Nb, and Zr across distinct lithological units. Analytical accuracy and method validation are rigorously monitored via dedicated halogen measurements of international certified reference materials. This integrated data package serves as a high-resolution benchmark for tracking volatile recycling and rare-metal metallogeny in highly evolved peralkaline granitic systems.

The dataset was generated through an integrated analytical workflow combining automated quantitative mineralogy, whole-rock geochemistry, high-precision halogen analyses, and micro-analytical mineral chemistry. Mineral modal abundances and textural domains were determined using a TESCAN Integrated Mineral Analyzer (TIMA) field-emission SEM system operated in dot-mapping mode with BSE and EDS signal acquisition. Whole-rock major element concentrations were measured by X-ray fluorescence (XRF), and trace elements by quadrupole ICP-MS. Whole-rock fluorine was quantified via alkaline fusion followed by ion-selective electrode (ISE) measurement, while chlorine, bromine, and iodine concentrations were determined using an ammonium hydrogen fluoride digestion method coupled with sector-field ICP-MS, with data accuracy cross-verified by pyrohydrolysis-ion chromatography. Major element compositions of halogen-bearing minerals, accessory phases, and fluoride melt inclusions were measured by field-emission electron probe microanalysis (EPMA), employing defocused beams and specialized background integration protocols to mitigate volatile and alkali migration. In-situ mineral trace element compositions were quantified using a 193 nm excimer laser ablation system coupled to a quadrupole ICP-MS, with electron microprobe data used for internal standardization. Data quality was monitored throughout all analytical sessions by repeated analyses of international certified reference materials.