Yixing Clay Teapots that Change Color -- Tianqing Clay
会变颜色的紫砂壶
All clay teapot changes color when fired. It is its drastic change of color after usage not after firing which makes it a Tianqing clay .
After soaked in water for 10 days and cleaning, the pine leaves turn greenish
After soaked in water for 10 days , the teapot turns greenish