Azure mud, with delicate raw minerals and blue color, was produced in the middle of Qing Dynasty and was once found in Dashuitan Mine in the center of Dingshu Town. After pottery, it is dark liver color, after soaking, it is green with green, and the greener the better. Azure mud is a kind of mud named after the color of the original purple sand ore. The general cultural level of ancient purple sand industry is not high, and it is often named simply and directly according to the color of mineral materials, which has been used to this day.
According to ancient records, the azure mud of azure mud teapot is mainly produced in pear trees in Huanglongshan mining area, where purple sand was mined, and then underground veins were dug and submerged, turning it into a big water pool, which is called Dashuitan mining area. Dashuitan is located in Yangshan Mountain, Huanglong Mountain, with the earliest mining and the richest ore beds.
Azure mud is produced under blue-gray purple mud, with uniform minerals, fine texture, purplish brown and slightly red dense block, fragile and slightly hard, with a small amount of muscovite fragments, shell-like texture on the surface, white wax (white spots will be formed after firing), and purple-black and slightly red cross-section.