Bottom trough clear is a kind of high-quality purple mud, which is produced in No.4 well of Huanglongshan, followed by No.5 well of Huanglongshan and Taixi Mine. Its colors are purple and blue, delicate and pure, very rare. The pot is red pig liver color, breathable and easy to foam. However, there are many bottom troughs in the market now, but there are few genuine ones, because since the No.4 well in Huanglongshan was sealed, the raw ore in the bottom trough can hardly be cleaned. Now, major pot manufacturers say that mud cleaning materials are hidden in the bottom trough, but in fact, they all use ordinary purple mud to make fakes.
Purple jade gold sand is a kind of mud made by general sand technology. It is to break the cooked sand into fine sand particles, spread them on the surface of the green body by spreading, beating and sprinkling, and then flatten them and embed them on the surface of the teapot, which is very suitable for the decoration and embellishment of the teapot. This kind of mud is generally based on purple mud and decorated with Jinsha, so it is called Ziyu Jinsha. But in terms of air permeability and bubble culture, it is not much different from the bottom tank.
To sum up, if they are all real mud, the bottom tank may be better. However, the current teapot market is very chaotic. If you don't know much about purple sand, it is recommended to choose an ordinary teapot.