Previous research describing kaolinite X-ray diffraction patterns predicted that disorders in the crystal structure cause the observed deformations of diffraction profiles. Although disorders, such as ±b/3 layer translations and random aluminum vacancies explain many of the profile shapes, they do not contribute to asymmetry in 00l profiles or the appearance of anomalous peaks in some diffraction patterns of poorly crystallized kaolinites. The disparity in measured values of kaolinite physical properties, e.g., unit cell dimensions, differential thermal analysis and infrared spectra, and free energy of formation, indicate the possible existence of multiple kaolinite phases. The presence of multiple phases is (theoretically) shown to cause certain observed diffraction effects that are not explained by random disorders. The use of a deconvolution technique to obtain X-ray diffraction profiles, free of instrumental aberration, confirms the presence of multiple, well-crystallized kaolinite phases in a sample of Keokuk, Iowa geode-kaolinite. Diffraction patterns of ground samples of Keokuk kaolinite indicate that phase changes, as well as ±b/3 layer shifts, occur with grinding. The existence of multiple, well-crystallized kaolinite phases may account for the physical properties of kaolinites as much as the sample's degree of crystallinity.