This is a new type of stone synthesized by more than 90% timely crystals, resins and other trace elements. It is a large-size plate pressed by a special machine under certain physical and chemical conditions. It is a non-plastic raw material, and the mullite crystal generated by it and clay at high temperature gives porcelain high mechanical strength and chemical stability, and can increase the translucency of the blank, so it is a good raw material for preparing white glaze.