A drawback of MAS NMR is that the presence of species that exhibit paramagnetism in substantial quantities (e.g. Fe, Mn), and mineral particles that may be ferro/ferrimagnetic (e. , significantly degrades the spectral quality . These phenomena present an obstacle to studying clays that also contain Fe-based minerals (typically goethite and hematite). Fe-rich clays are abundant in regions of the world projected to have a high demand for construction in the coming years (e.g. the Indian subcontinent, West Africa). The kaolinite present in lateritic clays can vary with regard to its particle size, degree of structural ordering and extent of octahedral Fe 3+ substitution, depending on its position in the weathering profile . There is an established trend between the amount of Fe substitution in a kaolinite specimen, and its extent of structural disorder . There is increasing research interest in using Fe-rich clays for cementitious materials' precursors, due to the relatively low dehydroxylation temperatures of disordered kaolinites , and the potential for Fe to participate in binder phase formation . Hydrochloric acid treatments have been used to remove Fe oxide and (hydr)oxide minerals from clay ; whilst such treatments have been adapted to avoid altering the kaolinite structure as far as possible, it is well-established that acid treatments tend to result in preferential dissolution of Al 3+ .