YINCHUAN -- Porcelain wares unearthed in Northwest China's Ningxia Hui autonomous region, which were produced nearly 1,000 years ago during an ethnic minority-ruled dynasty, bear high resemblance to those made in the "porcelain capital" of Jingdezhen in East China.

Archaeologists believe that the findings in Ningxia serve as evidence of the country's multi-ethnic integration at that time.

Remnants of the Suyukou kiln were discovered in 2017 in Yinchuan, capital of Ningxia, and cover an area of roughly 40,000 square meters.

From 2021 to 2024, archaeologists from the Ningxia Institute of Cultural Relics and Archaeology and Fudan University excavated around 2,400 square meters, finding remnants of workshops featuring six furnaces, as well as pits where workers used to mine porcelain clay, coal, quartz, lime and other raw materials and fuels, which were needed to make porcelain.

The fine white ceramics discovered at this site exhibit delicate textures, warm glaze, and glittering and translucent effects -- which are very similar to those found in Jingdezhen in Jiangxi province.

Judging from its production scale and saggars marked with the character guan, which literally means official, archaeologists believe that the Suyukou kiln was an official kiln producing bowls, cups, plates and other daily utensils -- mainly for the royal family during the Western Xia Dynasty (1038-1227).

Qin Dashu, a professor with the School of Archaeology and Museology at Peking University, noted that such white ceramics were popular among aristocrats and scholars during the Northern Song Dynasty (960-1127).

"Song and Western Xia used to be on good terms and had close technological and cultural exchanges," he said. "It is likely that the Northern Song officials sent excellent craftsmen to the Western Xia and helped them produce this fine white porcelain."

Based on their studies of the porcelain discovered at the site, archaeologists concluded that quartz content and performance parameters there were near to or even reached the technical standards of modern "high quartz porcelain" -- making these wares the earliest discovery of "high quartz porcelain" in China.

According to Zhu Cunshi, head of the Ningxia Institute of Cultural Relics and Archaeology, porcelain clay mined near Suyukou features high aluminum oxide content, which makes it difficult to produce such delicate white porcelain.

"The craftsmen creatively added quartz to the clay to increase the proportion of silicon dioxide and reduce the proportion of aluminum oxide, so as to create products similar to the ceramics from Jingdezhen," he explained.

These findings show that China's porcelain "dual formula" technology can be traced back to the earlier Western Xia Dynasty, and thus did not originate during the Yuan Dynasty (1271-1368) as previously believed, said Zhu.

The Suyukou site is believed to be the earliest Western Xia Dynasty kiln site found to date in China. Li Zheng, a researcher with the National Cultural Heritage Administration, noted that the discovery of the Suyukou kiln for the first time explains the origin of ceramics used by the Western Xia royal family -- thereby answering an important archaeological question in terms of China's ceramic development history.

"The Suyukou porcelain kiln site, integrating the high-end kiln industry technologies of both south and north China at that time, is an important demonstration of the official technical and cultural exchanges between the Western Xia and Northern Song dynasties, and a reflection of the integration of multi-ethnic exchanges in ancient China," she said.