Certified reference materials for calibration of the Thermo Scientific™ Niton™ XL5 Plus handheld analyzer

This dataset provides the major oxide (wt%) and trace element (ppm) compositions of certified reference materials (CRMs) employed in the calibration of the Thermo Scientific™ Niton™ XL5 Plus handheld analyzer. The collection spans a wide range of igneous compositions (ultramafic to felsic) and includes materials from the United States Geological Survey (USGS) and the Geological Survey of Japan (GSJ). Each entry specifies the sample name, source institution, rock type, GeoReM identifier, and the primary reference for compositional values. The data are presented in tabular format, with oxides reported in weight percent and trace elements in parts per million. This compilation ensures reproducibility of the calibration and supports transparency in pXRF workflows. The dataset can also serve as a resource for researchers seeking standardized compositions of widely used geological reference materials.