The history of sample preparation, and the need for interelement corrections during XRF analysis of cement, and their connection to historical ASTM C114 rapid method qualification requirements was presented previously at the 2007 ASTM Symposium on Test Methods in Tampa, Florida. It developed the interconnection between manufacturing trends, materials, XRF instrumentation and software capabilities to show why certain sample preparation methods were adequate at one time but may not be adequate any longer. For instance, the pressed powder method of sample preparation for XRF analysis of cement is limited to Portland cements meeting Specification C150 and is generally not applicable to the analysis of blended cements, including those blended with silica fume, limestone, pozzolans, fly ash, slag, and any combination thereof higher than the amounts of additions found in Portland cements meeting Specification C150. The fusion method is necessary in these cases, and any case where the mineralogical nature of the cement is not clearly known. If the testing facility is uncertain as to the nature of the cement or if the cement is not manufactured at the local plant, the fusion method is the best practices way to prepare the specimen for analysis, in order to insure an accurate analysis. Examples from the recent ASTM round robin tests on cements containing significant amounts of slag, fly ash and limestone will be used as examples of why the fusion method is necessary, and preferred over the pressed powder method. A universal method using the fusion method of sample preparation for the analysis of portland cements, blended cements, cements with additives and most all of the raw materials used to make these products will be described. Calibrations using both NIST and JCA (Japan Cement Association) reference materials for calibration will be shown to meet both ASTM C114 and ISO ISO/DIS 29581-2 specifications. The reason that fusion is necessary to obtain accurate analysis will be explained.