Zisha
Yixing clay (Zisha) is mainly mined in mines in Huanglongshan and Zhaozhuangshan, although the scale of mining is severely limited due to high demand. At the same time, the clay forms the basic quality characteristic of a Zisha Hu, which also influences its suitability for certain types of tea. The higher the porosity and purity of the clay, the better the teapot can round out bitterness and absorb the aromatic compounds and oils found in the teas and release them over time to subsequent infusions, thus achieving a significant increase in flavour complexity. This is why Yixing teapots are also known as "memory teapots", and are particularly suitable for use with one or at least several similar teas.
Dark red clay (Zhu Ni)
Dark red clays with a high iron content, such as Zi Ni, often acquire a smooth and shiny surface after firing. Due to the high demand for Yixing teapots, mining is very limited. These teapots are suitable for lighter, floral oolongs and Sheng Pu Erh.