Purple clay is indeed a unique raw material in Yixing. It has the necessary chemical and mineral composition for pottery making. From microscopic observation, it is found that the main minerals of purple mud are quartz, clay, mica and hematite. At the same time, the particle composition of these minerals (the size of naturally formed particles) is similar to the raw materials for porcelain in southern China, that is, its mineral composition is clay. The reasonable chemical, mineral, and particle composition gives purple clay excellent process properties such as good plasticity, high green strength, and small drying shrinkage.

To identify the quality of a purple clay teapot, you should start with its clay material, workmanship, style and other aspects. The purple clay teapots currently on the market can be roughly divided into two categories. One type is low-quality pots without any collection value, and the other type is purple clay pots with collection value. The raw materials of inferior pots are often low-grade mud such as casserole mud and vases. Its color is shiny and dull. After breaking it, you can clearly see the different colors of the inner and outer layers. The price of such pots often ranges from a few yuan to dozens of yuan, and they have basically no collection value. The mud used in real purple sand pots is made of weathered, crushed and blended purple sandstone. It has the characteristics of not being bright in color and not greasy in texture. The market price of pots made of different grades of purple sand mud varies greatly. difference.

As a purple clay teapot that is both practical and artistic, it is very particular about its workmanship. The proportions of all parts of the pot body are coordinated, and the transitions between points, lines, and surfaces are clear and smooth. The height of the spout and spout should generally be at the same level. When pouring water, the water flow will be in the shape of a water column and will not diverge. The spout and lid are tightly integrated and natural. If you press the vent hole on the lid, no water will flow out when you pour water. We can also start from two aspects. One is from the bright color. The real purple clay teapot is heavy and purple in color. Because it has been touched by human hands for a long time, it shows a moist luster. Generally speaking, the texture of newly made purple clay teapots is relatively loose, and the color is yellowish. There are less shiny ones and more dull ones. Even if there is shine, it is polished with state white wax.

Since whether it was made by a famous artist has a great influence on the collection value of a purple clay teapot, the mark on the teapot has also become one of the important factors in determining the value of the purple clay teapot. The seals of purple clay pots are usually placed on the bottom, lid, handle, etc. The makers of good purple clay teapots pay great attention to the layout of the stamps when stamping. Generally, the size is reasonable and the depth is moderate. There will be no blurring or over-deep stamping, and marks can be touched on the inner wall of the pot. Only those with the above characteristics can be called a purple clay teapot with collectible value.

As for good pots being expensive, you get what you pay for. Of course good things are valuable~