Dear Colleagues, We would like to draw your attention to our 2-days pre-Goldschmidt workshop on *Saturday/Sunday July 8-9 *entitled Ore-forming processes and metasomatism: combining experimental and modeling methods to interpret field observations | 2-DAY IN-PERSON WORKSHOP <https://conf.goldschmidt.info/goldschmidt/2023/meetingapp.cgi/Session/4557> The workshop is intended for graduate students, researchers, and professionals who want to learn how to apply the GEMS code package ( http://gems.web.psi.ch) coupled to the MINES thermodynamic database (*https://geoinfo.nmt.edu/mines-tdb/ <https://geoinfo.nmt.edu/mines-tdb/>*) to geochemical modeling, as well as learn about how to use current experimental methods regarding fluid-rock equilibria to interpret the evolution of natural ore-forming systems at elevated P-T conditions. The workshop will cover: 1) fundamentals of the GEM-Selektor code package and thermodynamic databases for simulating fluid-rock systems; 2) the GEMSFITS parameter optimization tool for optimizing thermodynamic properties against experimental data; 3) an overview of experimental advances in the study of aqueous complexes and mineral solubilities in hydrothermal fluids; 4) the stability and mobility of metasomatically induced and altered REE mineral phases in crustal rocks (e.g. monazite, xenotime, apatite, allanite, and titanite); 5) insights from field case studies of critical mineral deposits. Cheers, Alex Gysi, Dan Harlov, Dan Miron, Dmitrii Kulik, Nicole Hurtig, and Ruiguang Pan