Ceramics, shells and gemstones have been found at the site of a 1,000-year-old city in Northwest China's Xinjiang Uygur autonomous region, archaeologists said Thursday.

The city, known as Dalt and believed to have been built in Song (960-1279) or Yuan (1271-1368) dynasties, was discovered in 1985, when a farmer unearthed a silver coin while ploughing a field. Dalt lies on the Silk Road, with routes to Kazakhstan, Russia, and central Asia.

Excavation of the site began in June, with archaeologists using digital technology for information collecting to build three-dimensional images of the city's layout, according to Dang Zhihao from the regional cultural relics and archaeology institute.

Archaeologists have unearthed pieces of pottery up to 10 kilometers away, and found the ruins of a moat to the south and west of the city. They also discovered the bases for three beacon towers.

Within the city, they have collected close to 300 items including pottery, stoneware, ironwork, bronze and bones. They found porcelain from China's inland cities, shells from the coastal areas, and lapis lazuli and amber from west or central Asia.

"These items show that Dalt was an important city on the Silk Road, with booming trade and exchanges," Dang said.

Archeologists also found a large amount of glass fragments and iron smelting waste, which suggested a high level of development, he added.

The Persian word "bolat," which means steel, was earlier identitifed on the silver coin found by the farmer, leading many to believe that Dalt was the "steel city" Bolat mentioned in historical records.

According to a book written by Liu Yu during the Yuan Dynasty, Bolat was prosperous and has "a large number of houses had colored glaze as the windows."