Abstract
Although sulfur is a relatively abundant element, measurement results with small uncertainties remain challenging to achieve, especially at S mass fractions below 100 μg g ‐1 . We report > 1700 measurement results of S for thirty‐seven geological reference materials including igneous, metamorphic and sedimentary rocks, and one soil. Measurement results were obtained in two laboratories (Macquarie GeoAnalytical and Géosciences Montpellier) over a long period of time ≈ 25 years (1997–2022), using several measurement procedures: X‐ray fluorescence, high temperature iodo titration and elemental analysers equipped with thermal conductivity and/or infra‐red detectors. Sulfur mass fractions for these diverse geological reference materials range between 5.5 and 11,395 μg g ‐1 . While the comprehensive data set reported here should contribute significantly to a better characterisation of the S mass fractions of widely used geological reference materials, computed uncertainties, data distribution and comparison to published values still indicate heterogeneous distribution of S carrier(s) and analytical bias.