ZiSha clay comes in an often bewildering range of different types. In this section, Wan Ling Tea House aims to give you an overview of some of the main ZiSha clay types, the characteristics, clay names and general information to help you get even more from you YiXing teapot and tea wares.
The key ZiSha clay types are listed below.
Zi Ni is the most common ZiSha clay type. As purple clay is purple brown, ZiSha clay lovers used to call it 'black purple clay'. Zi Ni is widely accepted by the market as a great general purpose clay for YiXing teapots. Genuine purple clay is extracted from the ZiSha undressed ore in Huang Long mountain (黄龙山), a mountain located in the YiXing, JiangSu province
locality. Zi Ni ZiSha clay has a high content of iron (Fe); a large and loose structure which forms a bilayer porosity structure that allows excellent air and porosity convection. Due to these natural characteristic Zi Ni will respond well in terms of appearance changes with regular use.
The variation in mineral content varies widely, hence the wide range of 'colours' associated with this clay type. Likewise there is a wide range in the quality of Zi Ni.
Genuine Di Cao Qing clay, is once again mined from Huang Long mountain in YiXing county, JiangSu province. Zi ni undressed ore can be roughly divided into 3 kinds: tou cao qing (头糟青) i.e. mined from the top of the mine, er cao qing (二糟青) i.e. from the second level of the mine, di cao qing (底糟青) i.e. from the bottom of the mine. Di cao qing is produced from the bottom of purple clay pit which yields the best quality. Because of the high quality of this ZiSha clay, Di Cao Qing clay has been highly praised by clay artisans since ancient times, and regarded as superb material for a range of products. Di Cao Qing clay was a favourite clay of great artist Mr. Gu Jing Zhou.
The name of di cao qing is directly translated from YiXing local language. Di cao qing was produced from Huang Long mountain No.4 pit at first, in recent times from No.5 pit and TaiXi mineral clay pit. It's pure texture, exquisite shale, consistent brown colour has meant di cao qing clay is widely used by YiXing teapot makers in modern times.
Kiln temperature: about 1180c.
Qing shui clay is prized for it's looks. YiXing teapots crafted from Qing Shui Ni have a natural simplicity and feeling of age. Qing Shui Ni develops a strong and mature colour from long term use. Qing shui clay has been widely used by artisans since ancient times and so it is well represented in museums and private collections of antiques.
Qing shui clay is appreciated by artisans for it's easy to handle characteristics. This ZiSha clay is stable whilst retaining a reasonable stickiness, thereby making it easy to shape. Old qing shui clay must be extracted twice, or it will produce black edge and impure colour. But make sure no Fe2O3 and limy when extracting. Qing shui clay is a kind of pure purple undressed clay, YiXing teapot artists call it 'pu ni' (普泥), or common ZhiSha clay. However, high quality qing shui clay are rare and pricey, though inferior qing shui clays are plenty and cheap.
Duan Ni undressed ore, is also known as 'lao tuan ni' (老团泥), produced in Huang Long mountain, YiXing county. Appearance is almost white, with little dark green spots. In addition to being used to make pottery, Duan Ni can be also ground into powder which is used to to make the 'grit' or fleck effect some artists enjoy using on YiXing teapots and wares. Once fired, Duan Ni are said to have a 'goose yellow' colour, sometimes with a few red spots inside.
Another undressed ore duan ni is 'ben shan' green clay, also from Huang Long mountain. It is green gray colour, is a middle butter in the middle of purple clay, then turns into rice yellow after firing. Ben Sha Duan Ni is a course, large grit clay which makes for a good bilayer porosity structure, so having good air and liquid convection properties. The clay's properties mean that YiXing teapots made with Duan Ni rapidly take on characteristics from the chosen tea.
Old duan ni is a naturally formed clay mix. Old Duan Ni ZiSha clay occurs between layers of 'ben shan' green clay and purple clay undressed ZiSha ore. Old duan ni shares many of the same character with ben shan green clay and purple clay, it consists of cooked clay which can be stored for a long time.
Other Duan Ni ZiSha clay sub-types including golden duan ni and sesame duan ni clays.
Zhu ni: red color, smooth touch, making water softer, etc. it turns into bright red colour immediately after meeting boiling water, purple color indefinitely appears on the body of teapot, this mysterious spirit make tea pot lovers feel drunk. Using red clay tea pot, tea water is bright and lovely, smell is long and fascinating, taste is sweet and mellow.
Hong Ni has a naturally high contents of Fe2O3, Ferric oxide or red iron oxide as well as quartz and mica. Good examples of Hong Ni ZiSha clays are bright and clear, with an orangey red colour; poor examples dull and lifeless. Hong Ni red clay undressed ore is hard like a stone with a grassy green colour. Hong Ni is difficult clay to work with. Too lower temperature will cause the finished YiXing teapot to be dull and of a poor colour. Whereas a too higher temperature will cause the teapot to misshape and in some cases collapse. A typical kiln temperature is around 1100c.
Da hong pao red clay is bright red, which crafted in to a well made YiXing teapot looks amazing and elegant. Genuine Da Hong Pao is the deepest red clay, and much sort after. Quality examples of these clays are increasingly rare in the market place these days.
As ever it is important to have a trusted source. Ideally by working with a trusted tea shop such as Wan Ling Tea House and respected artists who have grown up in YiXing you will ensure that you receive genuine ZiShi clay at a fair market value, proportionate to the quality of the clay. With the growing demand for ZiSha clay products, not just YiXing teapots, many high quality clays are in shortage, not only pushing up prices but also making the market more attractive for fake teapots made of ZiSha clay mixed with other clays or worse still from clays not from the region at all.