According to the book "Yixing Zisha Mineral Materials", the real raw ore Da Hong Pao refers to Huanglong Mountain Bright Red Mud , and the color of this raw ore mud itself is bright red.
Huanglongshan Bright Red Mud: produced between the white mud and mud layers in the superficial yellowstone interlayer of Huanglongshan, it appears occasionally, and the mineral content is extremely rare. The appearance of the mineral material is a large red cloud-like dense structure, which is relatively hard and contains a certain amount of fine white mica fragments. The surface has a grease-like luster and is insoluble in water. There is a small amount of turquoise interlayer in some mineral materials. If it is not removed, white sand spots will appear after firing.
The appearance of the raw ore is flaky, hard as stone, dense and thick, and the surface is shiny and oily. The older stone red mud is red and purple, and the younger ones are bright rose red and red. The bright red mud is made of unit ore refining mud. The high-quality material of the pot is a rare mineral in the red clay category, and the reserves are very small. Cooked clay has slightly poor plasticity, is extremely crisp when formed, has a certain amount of sediment when produced, has high requirements for forming, and has a wide range of firing temperatures. Generally, it is fired at about 1120~1150°C, and the shrinkage rate is about 5.5%.
It is bright red after firing, and its surface grain texture is roughly the same as that of purple clay, which is in the shape of thin pear skin. The tire is pure and moist, and its luster is like jade.
