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We present new reference values for nineteen USGS, GSJ and GIT-IWG rock reference materials that belong to the most accessed samples of the GeoReM database. The determination of the reference values and their uncertainties at the 95% confidence level follows as closely as possible ISO guidelines and the Certification Protocol of the International Association of Geoanalysts. We used analytical data obtained by the state-of-the-art techniques published mainly in the last 20 years and available in GeoReM. The data are grouped into four categories of different levels of metrological confidence, starting with isotope dilution mass spectrometry as a primary method. Data quality was checked by careful investigation of analytical procedures and by the application of the Horwitz function. As a result, we assign a new and more reliable set of reference values and respective uncertainties for major, minor and a large group of trace elements of the nineteen investigated rock reference materials

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We report new data on the melting curve of H2O in the range 20–90 GPa and 1000–2400 K obtained in a laser-heated diamond anvil cell. We found a marked discrepancy between our present results and previous work which covered the pressure range up to 38 GPa. The melting curve shows a discontinuous change in slope at about 43 GPa, indicating a first-order phase transition most likely to the ice X phase. We could find no evidence for a strong dissociation of H2O up to 200 K above the melting temperatures.