Yixing (pronounced ee-shing) teapots first appeared during the Sung Dynasty (960-1279) in a region of China, located in the Jiangsu province. The Jiangsu province is the world's only source for the unique clay from which Yixing teapots are made, called purple or red clay.PURPLE CLAY (ZISHA) is also known as 5 colored clay because its basic colors are, red, yellow, green, blue and purple. Purple clay's unique properties make it ideal for brewing tea. The porous nature of purple clay absorbs the flavor, smell, and color of the tea that is brewed in it. Over time, Yixing teapots develop a seasoning from repeated use, making the tea brewed from a well used teapot a special treat. For this reason, most people will dedicate a single flavor of tea to a specific Yixing teapot.