Specific Yixing Ore and Zisha Clay

Listen to the Editorial Conversation for this chapter:

“Teapots made from such clay are able to enhance the color, fragrance, and flavor of tea. Those made by renowned craftsmen weigh very little but cost 10 to 20 pieces of gold. As a result, the price of gold now is rivaled by the price of such clay.”

- An account of Yang Xian Renowned Teapots (阳羡茗壶系, Yang Xian Ming Hu Xi) Published c. 1640 by Zhou Gaoqi (周高起, c. 1596 – 1650, late Ming dynasty).

The major categories of zisha (zini, hongni, zhuni, duanni, and luni) have been accepted categories of ore and clay since at least the mid-Qing dynasty. Each major-category exhibits unique properties, varying in ore color, ore-texture, ore-mineral composition, fired-clay color, fired-clay porosity, fired-clay heat retention, and fired-clay surface texture; the unique properties of each major category yield variations in a teapot’s interaction with each class of tea[1]– such that the interaction between clay and tea is, at least partially[2], a material property of the fired ware.

To understand the material properties of the fired wares, one must study the natural properties of the ore, the effects of processing ore into clay, the variations in processing technique applied to each major-category of ore, the blending of zisha and non-zisha clay to make usable wares, the effects of firing (including time, temperature, fuel, and kiln design), and the resulting wares’ interaction with a variety of teas. The intentional or unintentional differences in material and processing join with the natural variations of the ore to create a meta-material with distinct material-properties that can be optimally paired with zero[3], one, or more teas – independent from the non-material properties of the teapot formed from the material[4].