The Chott el Djerid is a large salt playa situated in southern Tunisia. The playa has a brine- type of Na-K-Mg-Cl-SO4and a stable mineral assemblage of gypsum (CaSO4.2H2O), halite (NaCl) and carnallite (KMgCl3.6H2O). From laboratory spectra of the three stable evaporite minerals it was found that gypsum and halite were the only evaporite minerals likely to be differentiated using Landsat TM imagery.