Soil samples treated in the field (Crowley, Texas) with a hydrogen ion exchange chemical (HIExC) solution over two years ago, were analyzed in the laboratory using different techniques, such as X-ray diffraction, zeta potential, transmission electron microscopy/ energy dispersive X-ray analysis and environmental SEM to better understand the mechanism of soil stabilization by the HIExC solution. A limited number of engineering properties such as swell-shrink, strength, and permeability were also tested. Untreated soil samples from the same location were included as a "control," to help delineate the intricate changes in the soil structure and engineering properties that occur as a result of the amendment with HIExC solution. The principal conclusion of this study is that a change in the shrink-swell behavior of smectite in soils treated with HIExC occurs, which is distinctly beneficial from the standpoint of its stabilization