When we talk about zhusha now, it refers to a different concept than in the Ming and Qing dynasties. During those periods, “zhusha” referred more to the color, meaning a color similar to “zhusha,” rather than the actual mineral. People would typically call deeper red zuni Teapots “zhusha” and lighter red ones “haitang red” (common red clay teapots).

Modern zhusha belongs to one type of zuni clay, emphasizing not only the similar color but also the “quality” (grit). In the industry, zuni clay that has prominent particles and a strong gritty feel after firing is usually called “zhusha.”

(Zuni Clay)

Zhusha and zuni clay are essentially the same type of clay, so their mineral compositions are basically the same. The difference lies in the fact that zuni clay has a relatively shorter weathering time, a higher proportion of clay minerals, lower quartz content, greater shrinkage, and a lower firing temperature;

On the other hand, zhusha has a longer weathering time, transforming from clay into mudstone with a richer quartz content, less shrinkage, and a higher firing temperature.

Due to the relatively lower content of silica in zuni clay and a higher proportion of clay minerals, the clay appears finer and denser after firing, with high vitrification and good gloss, and a section closer to porcelain, although its breathability is slightly inferior. Zhusha, on the other hand, has a rough surface, a strong gritty feel, and better breathability.

(Zhusha Clay)

While the distinction between zhusha and zuni clay is quite clear in their raw state, it can be difficult to differentiate them once they're made into teapots. This is because zuni clay, after being mixed with sand (known as “tiaoshazuni”), acquires a texture similar to zhusha. By adding a certain proportion of semi-mature or mature sand particles to zuni clay according to a predetermined plan, the resulting clay looks very much like zhusha and significantly improves the success rate of forming and firing.

Zuni clay processed to a smaller mesh size also has a texture similar to zhusha, with the texture becoming stronger as the mesh size decreases. Thus, true zhusha and tiaoshazuni are often hard to distinguish.

However, sometimes tiaoshazuni teapots and zuni clay teapots processed to a smaller mesh size may have relatively uniform particles on the surface and a slightly less clear texture.

Zhusha teapots have bright colors and better thermal shock resistance compared to zuni clay. They have a stronger texture and better breathability, making them excellent for brewing Tea, preserving its color, aroma, and flavor even after several days without spoiling, truly making them great vessels for authentic tea.