Core samples have been taken for complementary laboratory seismic measurements and mineralogical analyses on whole rock core from the COSC-1 borehole, Sweden (UTM 63.3124, 13.5259). These samples were used to provide and characterize the seismic properties (i.e., seismic velocities and anisotropy) of the drilled rocks from the highly metamorphosed and deformed Seve Nappe Complex, an orogenic thrust zone in the Scandinavian Caledonides, in central Sweden. The laboratory seismic and mineralogical analysis in general comprises three distinct measurements (i.e., data sets), which will be described in detail in the following subsections: (1) P- and S-wave laboratory seismic measurements on three perpendicular core plugs, under different confining (hydrostatic) pressure conditions (10 + 6 samples), (2) Bulk mineralogy of core plugs using X-ray powder diffraction (XRD) and mineral chemical composition measurements using an electron probe micro-analyzer (EPMA, here microprobe), on 10 thin sections and (3) Microstructural investigations based on electron-backscatter diffraction analyses on 5 thin sections. The laboratory seismic measurements were initially conducted on 6 samples by Wenning et al. (2016) and extended by another 10 samples by Kästner et al. (2020). Despite these authors were using the same sensor setup, the provided data files may differ due to individual acquisition parameters. Where different acquisition, processing, or calibration parameters are used this is indicated in the text using the abbreviations FK and QW referring to each examiner and their related sample measurements. International Geo Sample Numbers (IGSN) are provided for each core sample in the complete sample data table.