High- purity quartz ore, as a new mineral species, serves as an important raw material for the development of modern high- tech industries. The discovery of the Longquanping high- purity quartz deposit in the North Qinling belt represents a significant breakthrough in China’s exploration of pegmatite- type high- purity quartz deposits, but its genetic mechanism remains unclear. Methods: Based on detailed studies of ore deposit geological characteristics and petrography, columbite—tantalite and muscovite from the No. 10 high- purity quartz pegmatite in the Longquanping deposit were selected to carry out in- situ U- Pb, Rb- Sr, and 40Ar- 39Ar isotope geochronological research, aiming to constrain the formation age, metallogenic geological setting, and post- ore metamorphic modification history of the high- purity quartz deposit.Results: The results show that the U- Pb age of columbite—tantalite from the No. 10 pegmatite vein at the Longquanping deposit is 422.1±2.8 Ma, which is essentially consistent with the peak mineralization period (430~410 Ma) of rare- metal pegmatites in the region. These pegmatites were likely formed in a post- collisional extensional setting. The 40Ar- 39Ar and in- situ Rb- Sr ages of muscovite are 330.5±3.2 Ma and 306.0±15.0Ma, respectively, which are significantly later than the columbite—tantalite U- Pb age(422.1 Ma) but consistent with the previously reported metamorphic thermal event of 320~300 Ma in the North Qinling region. This indicates that the 40Ar- 39Ar and Rb- Sr isotopic systems in the pegmatite were reset during a later metamorphic event, thereby recording the metamorphic modification history experienced by the high- purity quartz pegmatite after its formation.Conclusions: Combined with petrographic characteristics of quartz, it is demonstrated that the Longquanping high- purity quartz pegmatite vein is similar to the pegmatite- type high- purity quartz deposits in the world, such as the Spruce Pine deposit in the United States and the Tysfjord deposit in Norway. After the formation of pegmatites, these deposits underwent multiple stages of metamorphic modification, leading to deformation and dynamic recrystallization of quartz, which facilitated the formation of high- purity quartz. Therefore, post- formation metamorphic modification may be a critical factor for the formation of pegmatite- type high- purity quartz deposits.