| The thickness of illite clay particles can be measured by powder X-Ray diffraction (XRD) peak-broadening techniques as described by the Bertaut-Warren-Averbach, BWA, method and by the integral peak-width, IPW, method provided the effects of swelling clay and XRD background noise are eliminated from XRD patterns. Swelling, if smectite is present, is eliminated by intercalating NA saturated Mite with polyvinyl pyrrolidone (PVP-10). Background is minimized by using polished metallic silicon wafers cut perpendicular to the (100) plane as a substrate for sedimentary illite spec, and by using a single-crystal monochromator in the XRD.; In this research XRD measures of PVP-intercalated sedimentary illite indicate that there are at least four types of crystallite thickness dilution shapes for illite particles, which appears to reflect the depositional environment of the clay. Measurements of mean particle thickness made by various techniques such as BWA, IPW, fixed canon content, and transmission electron microscopy give comparable thickness distribution results (Eberl et al., 1998b).; This method offers increased analytical precision and the convenience of using XRD to determine mineralogy as well as granulometry. The results suggest clay deposited under different environmental conditions may have different grain size distributions. |
