... purple clay tea cup1.Purple clay cup/mug can keep the tea and coffee in fresh taste 3 days without changing, 2.The cup surface with ... engraving together, so it with artistic culture3.The purple clay is a rare earth, from scientific research, purple clay does not contain lead, ... do harm to human healthy, whereas the research proves that purple clay contains SiO2, Al2O3, Fe2O3, MgO, CaO, these minerals ...