Several aspects of kaolinites (clays) will be investigated: 1) what possible defects are present in kaolinites, 2) do kaolinites from different geologic origins have different defect structures, 3) for those samples which appear to be mixtures of two kaolinites, can the two constituents be separated (if so, how do they differ crystallographically and chemically), 4) in kaolinite samples which show different crystal morphologies, are themorphologies related to different defect structures, 5) is there a relation between the defect structure of a kaolinite and its chemical composition, 6) is there a relation between the defect structure of a kaolinite and its ability to intercalate organic compounds? In addition to their scientific interest, clays are extremely important industrial and agricultural materials and their properties are critical to industrial and agricultural processes.