In collaboration with the Carnegie Institution of Washington and Virginia Tech's National Center for Earth and Environmental Nanotechnology Infrastructure, this field and experimental study investigates whether a link exists between the bioavailability of gypsum (calcium sulfate dihydrate) and the habitability of gypsum-dominated (i.e., gypsic) environments. The results may have direct implication for the current and past habitability of Martian surfaces dominated by gypsum deposits.