Clay is most commonly associated with the sublime experience of the European spa where visitors have been masked, soaked and basted with this touted curative since the Romans ruled. If ASU geochemist Lynda Williams and microbiologist Shelley Haydel's research on the antibacterial properties of clays realizes its full potential, smectite clay could one day rise above cosmetic use to take its place comfortably with antibacterial behemoths like penicillin.