The hydrothermal laboratory is equipped with horizontal and vertical cold-seal pressure vessels for the synthesis of crystals or glasses or to study interactions between minerals/rocks, melts, and fluids at hydrostatic conditions. An advantage is that long-term runs can be done to investigate equilibria between solid phases. This facility, operated by the Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, is open to all academic applicants, both national and international. There is no external steering board. Requests to use the laboratory are evaluated based on scientific quality and feasibility of the project.