Yixing ( pronounced Yee-shing ) is a small city that has become famous due to a unique type of clay that is only found there. This unique clay is called Zisha. Zisha Clay is found in five different colors...red, yellow, green, black, and purple. It has been used in pottery for over 3,000 years. The properties of the clay make it the perfect vessel for brewing tea. With use, the teapot absorbs the flavors of the tea which enhances future batches. Zisha Clay Teapot should never be washed with soap and water, just rinse with water and allow to drip dry.