This dataset contains mineral chemical compositions of hydrothermal precipitates, including those of talc and chlorite, collected at the Polaris hydrothermal field on the ultraslow-spreading Gakkel Ridge, Arctic Ocean. The samples were retrieved from 3,156 m depth by gravity coring at station PS101/180, R/V Polarstern Expedition PS101; besides the recovery of these precipitates in the core catcher the gravity core was empty. Major elemental compositions (in wt.%) were obtained via energy dispersive X-ray spectrometry. Details on the analytical procedure and uncertainties can be found in Albers et al. (submitted).