Qing Shui Ni, as is commonly known, is a type of purple Clay ore, with a reddish hue that can easily be confused with red clay. Many only know it as the material used for Flower pots in the past, and now used for Teapots. Knowing these few points only indicates a superficial understanding, as Qing Shui Ni is indeed a type of clay that is easily misunderstood.
Often, people ask how to distinguish between Qing Shui Ni and Di Cao Qing (Bottom Green Trench). Here's an example: clay derived from refining the original Di Cao Qing ore can be called Qing Shui Ni, but not all Qing Shui Ni is necessarily Di Cao Qing.
Qing Shui Ni refers to a category of clay made by refining a single type of ore without adding any other ores or chemical pigments. The key point is that it is made from a single type of ore! Any purple clay that does not contain additives or chemical materials can be referred to as Qing Shui Ni.
Qing Shui Ni is a general term referring to a category, not a specific type of clay.
The Qing Shui Ni used for making flower pots was different from this.
The Qing Shui Ni used for flower pots, in the 1960s and 1970s, was produced by combining leftover purple clay and red clay from Teapot production with ordinary purple clay at the No. 1 Purple Clay Factory. This combination was processed into what was called Qing Shui Ni, which was then used for low-grade, coarse flower pots.
Nowadays, generally, purple clay that is not mixed with other ores or chemicals and fires to a reddish color is called Red Qing Shui, while that firing to a purplish hue is called Purple Qing Shui.
Those who mistakenly believe that Qing Shui Ni is just an ordinary, low-quality clay are greatly mistaken. Specific types of clay should be evaluated individually.