Purple Jade, Gold Sand, the precious Yixing clay

Zini rock

I've borrowed the name of this article from a Chinese movie about Yixing zisha teapots 紫玉金砂. It cleverly inserts jade and gold into the character zisha. Since jade is the most precious stone in China and gold the most precious metal, these 4 characters mean that you zisha clay is very precious for what it contains, for what is between zi and sha! 

The key to understand zisha clay is to start with the rock that comes from the mine in Yixing. See above. What do you see? This zini rock is the most commonly found. Green and yellow rocks are more rare and I will discuss them in another post. Let's focus on this rock. There are 2 things that I would like you to notice. First, we can see other colors on it, here and there. It's not evenly purple, but there are lighter colored parts. Second, we can see on the lower right hand side that there are already small fragments that have come off. This rock is very friable and is easily turned into small bits. And since the original material from the mine also contains other colors, the clay should also display this diversity in colors.

Let's check this with this Yixing zini shuiping teapot from the 1980s.

Here a picture of the body:

And here is a close up of the above picture:

The granularity is quite obvious now. That's why it is called sha (sand).

It is easier to see it under direct sunshine. One can also see the marks left by the maker inside the teapot.

And what I like is the iridescence of the zini as reflects the sun. This nacre effect is obtained by these many grains that reflect the sun a little bit differently, because they are unevenly layered. 

Let's compare this zini teapot with my Qianlong reign (1736-1795) hexagonal enamel painted zini teapot.

Here is a first close up of the lid and upper part:

For more clarity, this image (shot with a macro lens) brings us even closer to the clay.

The difference is that in the eighteenth century, the potters didn't have much digging to do. The rocks on the surface belong to a different layer and had been more exposed to the sun and the air. The result is a smaller granularity. That's why the clay feels smoother and I had to enlarge the picture more. But we can see that the Yixing characteristic is similar. It's not just one color, but there are many colors of minerals that make up the clay.