Chemically, Salt is sodium chlride (NaCl). As packaged (right), salt grains look like broken and/or deformed cubes. When dissolved and allowed to recrytalize (below), salt crystals take on a distinct pyramid shape the outline of which is sometimes faintly seen in the orginal "cubes". Though salt can certainly be viewed with normal substage lighting, it looks more like salt and less like dirty ice when viewed under superstage lighting. Note that all of these images are at 40X, but weaker solutions make smaller crystals and medium concentrations produce much larger crystals.