Zisha Clay
Zisha is the iron-rich clay from the Yixing area of Jiangsu, China, used for unglazed teapots; its main types are zini, zhuni/hongni and duanni.
Definition
Zisha (紫砂, "purple sand") is a group of iron-rich stoneware clays mined in the hills around Dingshu town in Yixing, Jiangsu province. The clays are quarried as hard ore, weathered, ground and mixed with water into a workable body. Fired at roughly 1,100-1,200°C, they form a dense but slightly porous stoneware that is left unglazed. Potters group zisha into three families by color. Zini (紫泥, purple clay) is the most common, firing to purple-brown. Zhuni (朱泥, vermilion clay) and the broader category hongni (红泥, red clay) fire to orange-red; true zhuni shrinks heavily in the kiln and makes thin-walled, dense pots that are difficult to fire. Duanni (段泥) fires to a beige or yellow. Potters also blend clays and add natural mineral pigments. Huanglongshan, the most famous source of raw ore, was closed to large-scale mining in the mid-2000s, and stockpiled older ore commands a premium. This scarcity, combined with high prices for genuine pots, has made counterfeit and adulterated "zisha" common in the market.
In Depth
How it behaves: denser clays such as zhuni hold less water in the body and give a brighter, higher-aroma cup, often recommended for lightly roasted oolong. More open clays such as zini absorb more and are said to soften and round off strong teas such as shou pu'er and roasted Wuyi oolong. These effects are widely reported by brewers but modest.
Warning signs of fake zisha: a uniform, plastic-looking surface; color that rubs off on a damp cloth; a chemical or shoe-polish smell when filled with hot water; and identical pots selling at very low prices. Slip-cast pots are made from liquid clay poured into molds rather than worked from solid clay.
Treat any unverified pot as decorative until it has been bought from a seller who can identify the clay and the potter.
See Also
- Yixing Clay Types
- Chinese Ceramics
- Teaware Materials