Stone Red and Stone Yellow are also raw materials, though not for making Teapots directly, but rather for coloring through slurry. Therefore, it is inaccurate to say that a purple clay Teapot with added Stone Yellow or Stone Red is a chemical teapot. Due to their scarce production, high sand content, and extremely low plasticity, these materials cannot be made into Pottery alone. They are often ground into slurry and mixed with other minerals to improve the color of the final product.

For those who refine their own mud, Stone Yellow and Stone Red are cherished treasures. They are exceptional in the world of purple clay raw materials and indispensable ingredients in the refining process. They are in very limited supply and, when mixed into the mud, serve to adjust the color, increase the finish's luster, form patina, and lower the firing temperature of the clay.

The internal composition of the Stone Red and Stone Yellow ores also has its differences. For example, Stone Red contains a clay core and belongs to the category of red clay, which can be used to make teapots independently. However, its outer shell is a concretionary mineral, unsuitable for making teapots alone. Stone Yellow slurry presents a deep red color, while Stone Red slurry appears as a light purple (light pink at low temperatures and purple at high temperatures). Nowadays, Stone Yellow is commonly found in round, grape-like, or cylindrical structures; its shapes vary widely, from plate-like to egg-shaped, even resembling organic forms. It is formed within shale, clay, and other sedimentary rocks rich in pyrite. Generally, miners refer to spherical, cylindrical, or egg-shaped formations as “Stone Yellow,” while rectangular block or flaky ones are called “Stone Red.” There are also spherical Stone Reds, but they are exceedingly rare.

Typically, egg-shaped Stone Yellow has a dark red or black exterior, much like an eggshell. Miners in Yixing have also collected egg-shaped Stone Red from the Jiang Li Hong clay layer. This type of clay is extremely rare, making the teapots made from it particularly precious!

Stone Yellow has a strong sandy texture and very poor plasticity, leading to an extremely low yield rate. It is often sought after but difficult to obtain, making the creation of teapots challenging. Moreover, being pure Stone Yellow, the material contains a high iron content, resulting in a surface appearance similar to iron, exuding an ancient and rustic charm. The abundant iron ions are highly beneficial to health, making it a true Chinese iron teapot! Compared to Japanese iron teapots, it surpasses them in terms of raw materials and manufacturing difficulty! Because there are very few finished products on the market, few pot enthusiasts have had the opportunity to handle them, thus maintaining a veil of mystery around them.

When holding a finished teapot, one will feel a significant weight due to its high density, a result of the high iron content. Under high-temperature firing, the iron melts and seeps onto the surface, creating a strong metallic texture that is strikingly impressive. Its impact on the taste of Tea water is incomparable and cannot be replicated, enhancing the flavor to a richer, smoother level.