Many enthusiasts often discuss how to determine the authenticity of a purple clay Teapot, and one common point is:

Purple clay has its unique granular feel; if the surface of the pot feels rough to the touch, it's an authentic Purple Clay Teapot; if it feels smooth and fine, it's fake.

Is this statement correct? Let's discuss it today.

The “sand” in purple clay

Purple clay is a type of mineral that naturally contains quartz and other medium particles. Unlike porcelain, these sand particles are a feature of its firing process and a characteristic of purple clay.

▲ Original purple clay ore

This seems to confirm the above statement, but we still need to analyze it further.

The rough or smooth feel of a purple clay teapot depends on the fineness of its clay, measured in mesh size.

After the purple clay ore is weathered, it is ground into particles using a sieve, and the mesh size of the clay refers to the number of holes per square centimeter in the sieve.

▲ Ore sieve

Mesh is a unit of diameter referring to the number of small holes per square centimeter, with options like 24 mesh, 32 mesh, 40 mesh, 60 mesh, 80 mesh, 100 mesh, 120 mesh, etc.

The mesh size indicates the coarseness or fineness of the clay; the smaller the mesh size, the coarser the clay; the larger the mesh size, the finer the clay.

Generally, clay with a mesh size of 60 or below is considered coarse, resulting in a more prominent texture and granular feel, as well as better breathability.

The finer the mesh size, the smoother the surface of the teapot will be, such as with 120-mesh clay, which lacks the granular feel. Additionally, red clay (zhuni) tends to have a finer texture.

▲ Mesh size example

The granular feel of the teapot is also subjective to personal touch. What is considered coarse or fine can vary, so the granular feel of the teapot body can only serve as a reference, not a basis for judgment.

Smooth surfaces

The so-called fake purple clay Teapots are often slip-cast teapots or hand-pulled teapots with added water glass, and the clay used in these processes is usually very fine, typically over 200 mesh.

Therefore, these teapots tend to have a relatively smooth surface.

▲ Hand-pulled teapot

This might seem to confirm the initial statement, but we still need to analyze it further.

To cover up this smoothness, some people apply a layer of slurry on the surface of the teapot by spraying a mixture of sand and clay, then firing it again. This results in a granular feel on the surface of the teapot.

However, this granular feel differs from that produced by a coarse mesh size; the former is superficial while the latter is integrated into the body of the teapot.

▲ 60-mesh Ziye Shibo teapot

In conclusion

The rough or smooth feel of the teapot surface can only serve as a reference for determining authenticity, not as a definitive basis.

Evaluating a teapot requires considering multiple aspects; relying on just one factor is unreliable. Otherwise, you might be focusing too narrowly!