## Clay Material Test-Fired Samples Gu Jingzhou once published an article specifically discussing the characteristics of Yixing purple clay. Purple clay is the collective term for red clay (cinnabar clay), purple clay, and Tuanshan clay (native green clay, which appears rice-yellow in color). These three base clays vary in color endlessly due to differences in mining areas and mineral layer distribution, as well as slight variations in firing temperatures during the kiln process—fascinating and wonderful beyond words... Among them, vermillion, purple, and rice-yellow form the natural colors of purple clay ware. Vermillion has gradations from light to dark, purple has depths from shallow to deep, and yellow is rich in variation. There are cinnabar purple, aqua blue, agarwood, yellow-yellow, cold golden yellow, pear skin, incense ash, blue-gray, black-green, paulownia green, steel black, brown-black, pomegranate skin, and submerged black, among other colors. Upon careful observation, within each clay color there are also white sandy specks, like flashing points of silver sand. When reflected in sunlight, they appear like pearls. Or when coarse clay sand or grog is mixed into the clay, the texture appears throughout the body, with pearl-like qualities appearing and disappearing—even more striking. Various mineral soils produce multiple colors after firing, elegant and pure in their tea-like quality. Thus there is the refined color palette of "purple without excess, red without vulgarity, yellow without garishness, green without immaturity, ink without blackness, and gray without dullness." --- [1] Xu Xiutang, in Shi Jundang and Sheng Pansong, eds., *Spring and Autumn of Purple Clay* (Shanghai: Wenjiang Publishing House, October 1991 edition), pp. 6-7. [2] Xu Xiutang, *Yixing Purple Clay Teapots* (Hong Kong: Jinfeng Company, 1985 edition), Preface.