Chinese scientists have identified a rock formation in the Xizang autonomous region as a potential source of high-purity quartz. This scarce mineral is critical to manufacturing semiconductors, optoelectronics — light-based electronics, and aerospace technology.

The discovery marks a significant step toward reducing the country's reliance on imported supplies of this strategic material.

The research team, led by the University of Science and Technology of China in Hefei, Anhui province, evaluated leucogranites — light-colored igneous rocks formed when the earth's crust melts — in the Dinggye area of southern Xizang. They found these rocks could be purified to yield a silicon dioxide content above 99.995 percent, meeting the threshold for high-purity quartz. The findings were published in the European Journal of Mineralogy on April 30.

High-purity quartz is highly valued because it can withstand extreme heat, is chemically stable, does not expand much when heated, and is an excellent electrical insulator that allows light to pass through easily. Defined as having total chemical impurities below 50 parts per million — meaning the mineral is roughly 99.995 percent pure silicon dioxide — it is extremely difficult to purify. However, it remains essential to high-tech industries such as microchips, solar panels and fiber-optic communications.

Global resources of the mineral are scarce and unevenly distributed. According to the China Geological Survey, the United States holds some of the richest deposits. In fact, the Spruce Pine mine in North Carolina once supplied more than 90 percent of the world's semiconductor-grade high-purity quartz sand. Russia, Norway and Australia also maintain significant reserves. These countries have long dominated the market with established mining and processing capabilities.

China, despite being the world's largest manufacturer of solar panels and a major semiconductor producer, is the largest importer of high-purity quartz. Consequently, the country has been intensifying efforts to develop domestic sources.

In recent years, breakthroughs under the national strategic mineral exploration campaign have identified high-purity quartz deposits in the East Qinling region of Henan province and the Altay region of the Xinjiang Uygur autonomous region. These sites have yielded products with purities of at least 99.995 percent, with some samples reaching 99.998 percent. In 2025, the Ministry of Natural Resources officially designated high-purity quartz as China's 174th recognized mineral species, aiming to further bolster supply chain security.

The new study has extended that exploration effort to the Himalayan belt, which stretches across hundreds of kilometers in Xizang. While the light-colored leucogranites there have long been studied for their potential to host rare metals, no systematic assessment of their high-purity quartz potential had been conducted until now.

The research team collected samples from the Dinggye area and applied a series of analytical testing techniques. The results showed that the quartz in these rocks crystallized at unusually low temperatures between 451 and 569 C.

These cooler conditions are comparable to those found in pegmatites — a type of coarse-grained volcanic rock known to host high-quality minerals. This lower crystallization temperature is crucial because it limits the amount of impurities that can trap themselves inside the quartz's natural structure, making the material much easier to clean and purify.

After processing, the purified quartz sands from two sample types achieved silicon dioxide purities of 99.9969 percent and 99.9959 percent, successfully placing them within the high-purity category on industry-standard classification charts.

The study noted that the widespread exposure of these rocks in the region offers a significant opportunity to develop high-end quartz resources in China, ensuring a stable and strategic domestic supply of raw materials.

However, the researchers also noted that residual levels of lithium and titanium in the purified samples remain higher than those of the IOTA standard sand, an industry benchmark from the US. This indicates that further optimization of the purification process is required.