A comprehensive and statistically robust understanding of rock characteristics is essential for reservoir characterization of the deep subsurface to accurately plan exploration campaigns, parameterize predictive 3D geological models, interpret geophysical data, and execute numerical thermo-hydraulic-mechanical-chemical simulations, thereby reducing economic risks and project uncertainties. Despite growing interest in the crystalline basement in Germany for e.g., geothermal energy applications and the safe storage of high-radioactive nuclear waste, systematic datasets covering the major crystalline and metamorphic basement units and their physiomechanical characteristics remain scarce, fragmented, or lack the metadata required for robust evaluation. To address this data gap, the AMPEDEK project established a unified, multi-scale national reference database for geochemical, petrophysical, and mechanical rock properties of crystalline rocks in Germany. The framework integrated extensive literature reviews, data from geological surveys, and newly conducted sampling and measurement campaigns, linking metadata, geochemistry, petrography, and physiomechanical rock properties through unique sample IDs.</p> <p>Existing data from more than 40 studies were compiled, evaluated, and integrated into the database. In addition, approximately 650 cylindrical plugs retrieved from drill cores and outcrop samples were systematically analyzed with respect to their mineralogical, geochemical, petrophysical, and rock mechanical properties to close remaining data gaps. Particular emphasis was placed on sampling a broad spectrum of lithologies to ensure coverage of the major crystalline units in Germany.</p> <p>The resulting open-access repository (Weydt et al., 2026; <a href="https://doi.org/10.48328/tudatalib-2167" target="_blank" rel="noopener">https://doi.org/10.48328/tudatalib-2167</a>) currently contains approximately 25,700 data points covering up to 34 parameters measured on 8,200 samples from more than 3,400 sampling locations across eight federal states in Germany. It represents the first standardized national-scale compilation of geochemical, petrophysical, and mechanical rock property data for the crystalline basement in Germany. The database provides a robust empirical foundation for early-stage exploration, reservoir characterization, and the validation of analytical measurement methods. Future efforts will focus on expanding the database towards regions with low data density and on high-temperature and high-pressure experiments to improve the understanding of parameter variations under in situ conditions.