This paper is the result of mineral exploration engineering.

Objective A large amount of high-quality quartz resources is hosted in the Wudang area of the South Qinling. However, the low level of research on quartzite-type high-purity quartz raw materials restricts raw material quality evaluation and ore-prospecting breakthroughs in this region. This paper aims to investigate the geological characteristics, impurity occurrence states, and quality-controlling factors of Huishuigou quartzite-type high-purity quartz raw materials, so as to provide a basis for the evaluation and prospecting of similar raw materials in the area.

Methods Taking Huishuigou quartzite as the research object, various analytical methods including petrographic observation, fluid inclusion testing, XRD analysis, cathodoluminescence, ICP-OES, and LA-ICP-MS were adopted to systematically study its trace impurity content, occurrence states, and petromineralogical characteristics. A comparative study was also carried out with quartzites from the Melkfjell and Solør areas in Norway and the East Qinling alaskite-type high-purity quartz.

Results The total impurity content of Huishuigou quartzite ranges from 48.192-110.818×10⁻⁶, which decreases to 18.82×10⁻⁶-27.23×10⁻⁶ after purification, meeting the requirements for high-end high-purity quartz products such as the outer wall of quartz crucibles. Its quality is mainly affected by Al, K, Na, Ca, Mg elements and fluid inclusions. The temperature-pressure conditions of metamorphism are critical for the purification of quartzite, with 420-530 °C as the most favorable mineralization temperature range. Grain boundary migration induced by recrystallization enables the purification of quartz particles. Meanwhile, it is confirmed that the Shiyan-Baihe zone (Hubei-Shaanxi) has favorable geological conditions for the formation of quartzite-type high-purity quartz deposits, and differentiated prospecting and evaluation criteria should be established for different types of high-purity quartz deposits.

Conclusions Huishuigou quartzite can be used as a raw material for high-end high-purity quartz products. Metamorphic recrystallization is the core mechanism of quartzite purification, and fluid inclusions are the key factor restricting the quality of quartzite in this area. The western margin of the Wudang uplift in the South Qinling (Shiyan-Baihe belt) has good prospecting potential for quartzite-type high-purity quartz. The temperature-pressure conditions of metamorphism, fluid inclusions, and impurity element assessment are the core points for prospecting and evaluation in this region. The conclusions can provide an important reference for the regional quality evaluation and prospecting of quartzite-type high-purity quartz raw materials.