March 26, 2009 -- The world, to a great extent, is coming to know China through the chinaware it produced, and the country's porcelain was virtually used as a yardstick in evaluating Chinese civilization. Without the invention and development of fine porcelain, China's history would have been decidedly different.

Among the list of cultural heritage sites that ranked among the major archaeological finds in China in the 20th century are the three most widely known china kiln sites in the central province of Henan; namely, Ruyao kiln in Baofeng County, Junyao kiln in Yuzhou City and the Huangye tri-colour pottery kiln in the city of Gongyi. Owing to its status as precious imperial tributes, Ruyao kiln is widely considered as the pick of the bunch.

The 1,000-year-old Ruyao kiln was largely discovered in Qingliangsi village of Baofeng County, the largest celadon production site during the Song Dynasty(960-1279). In 2000, archaeologists unearthed, in what they believe to be the ruins of the main processing section of the facility, 15 furnaces, two workshops, various instruments, a number of glazing materials and fragments of Ruyao porcelain pieces. The discovery provided strong evidence on the official rank of the Ruyao kiln.

Throughout China's history, celadon pieces made at Ruyao kiln were sent as tribute to the imperial court and were famous for their azure glaze blended with agate. But the unique technique used by the kiln artisans was lost during wars in the late Yuan Dynasty (1271-1368), and the site of the kiln remained a mystery to Chinese archaeologists until recent times.

While celadon dominated the Tang Dynasty, chinaware became more colorful in the hands of artisans during the Northern Song Dynasty, who had learned to produce a unique red-tinged underglaze for porcelain with the red derived from copper.

In the early 12th century, an imperial kiln was set up to produce colorful porcelain pieces - mainly bowls, dishes, cooking vessels, vases and figurines - exclusively for the emperor and the imperial family. According to historical records, only 36 pieces were produced each year, none of which went into the collections outside the court.

Experts lament that no more than 70 pieces from the Ruyao kiln still exist, all of them in museums around the world and valued at US$10 million each.