The Tibet leucogranite as a potential high-purity-quartz raw material: first discovery and case study from the Dinggye area

This study evaluates Tibet leucogranites as a potential raw material for high-purity quartz. We systematically investigate the petrography, geochemistry, and purification potential of leucogranites from the Ama Drime Massif of the Dinggye area. Our results demonstrate that these leucogranites hold considerable potential to produce high-purity quartz with SiO2 contents above 99.995 %, highlighting their value as a new and extensive source of high-purity quartz in Tibet. Various analytical techniques, including optical microscopy, X-ray fluorescence imaging, X-ray fluorescence spectrometry, ICP-MS, and LA-ICP-MS, together with purification experiments, were applied to representative samples (XZ-BG and XZ-WJ). The results indicate that the leucogranites are composed predominantly of quartz, albite, and K-feldspar, with minor biotite, muscovite, garnet, and amphibole. These rocks display typical S-type granite characteristics and were likely derived from source regions comprising granitic gneiss and metamorphic shale. Quartz-hosted inclusions are dominated by relatively large primary inclusions and secondary fluid inclusions, which are comparatively easy to remove during purification. As a result, the purified samples yielded SiO2 contents of 99.996 % and 99.995 %, respectively. This work represents the first integrated mineralogical, geochemical, and purification assessment of Tibet leucogranites as a source of high-purity quartz and proposes temperature as a key ore-controlling factor. The widespread exposure of leucogranite in the region offers a significant opportunity to develop high-end quartz resources in China, ensuring a stable and strategic supply of high-purity-quartz raw materials.