IT is rare to see antique zisha (purple clay) teapots in city auctions but nine works by a Qing Dynasty (1644-1911) master will go under the hammer, so to speak, at The Regent Shanghai next Wednesday.

Famous zisha teapots are made from purple clay mined in Yixing, Jiangsu Province. They are known for brewing superb green tea. With use, the tea flavor is absorbed by the clay, and it is said that with a fine much-used old pot, you can just pour in hot water, no tea leaves, and get a perfect cup of tea with wonderful aroma.

The nine purple clay teapots to be auctioned were made by Chen Mingyuan, a Qing Dynasty master who was considered one of the most skilled. From the 1920s to 1940s, his teapots were coveted by Shanghai collections because of their unique shapes, colors and textures.

Chen was imaginative and carved the clay into shapes like eggplant, fruit or a root.

According to Ji Chongjian, owner of Chongyuan Auction House, Chen's teapots all have a clear provenance. They are from the collection of Chen Zhichu, a discerning art collector in old Shanghai.

"In China, zisha teapots are believed to have their own spirits," Ji says. "Its distinctive, earthy taste and deep reddish color is known for its many health-giving properties. It aids in digestion and fat metabolism."

Obviously, the antique teapots function more as an art piece than a functional utensil.

These teapots are estimated to each fetch 300,000 yuan to 400,000 yuan (US$43,920-US58,460).

The auction also features about 900 antiques ranging from traditional ink-wash painting, calligraphy to ceramics and jade. Most of them were consigned by the descendants of Chinese entrepreneurs or intellectuals living abroad.

"Providing provenance is one of the characteristic of our auction house, because there are so many fake pieces on the market," says Ji. "We guarantee that those pieces to go under hammer at our auction have a clear provenance."