We have developed a new database named GeoReM (http://georem.mpch‐mainz.gwdg.de) for reference materials and isotopic standards of geochemical and mineralogical interest. Reference samples include rock powders originating from the USGS, GSJ, GIT‐IWG, synthetic and natural reference glasses originating from NIST, USGS, MPI‐DING, as well as mineral (e.g., 91500 zircon), isotopic (e.g., La Jolla, E&A, NIST SRM 981), river water and seawater reference materials. GeoReM is a relational database, which strongly follows the concept of the three EARTHCHEM databases. It contains published analytical and compilation values (major and trace element concentrations, radiogenic and stable isotope ratios), important metadata about the analytical values, such as uncertainty, uncertainty type, method and laboratory. Sample information and references are also included. Three different ways of interrogating the database are possible: (1) sample names or material types, (2) chemical criteria and (3) bibliography. Some typical applications are described. GeoReM currently (October 2005) contains more than 750 geological reference materials, 6000 individual sets of results and references to 650 publications.