The physical properties of sea ice, including salinity, sea ice temperature, and sea ice texture as well as isotopic composition (oxygen and hydrogen) were analyzed from samples collected on the CAATEX 2019 expedition to the central Arctic Ocean (between North Pole and Svalbard) in late summer 2019. In addition, isotope samples were collected from precipitation, melt ponds, and under-ice seawater. Data was collected to understand the formation mechanisms of sea ice in the area. Ice cores were collected with an ice corer, and measurements (temperature) were directly carried out from ice cores after retrieval. From an additional ice core, samples (salinity and isotopes) were collected and melted onboard. Salinity of samples was measured onboard using a conductivity probe, while samples for isotopic composition were placed in sample bottles and measured at the FARLAB (University of Bergen) after the expedition . A complete ice core was brought back for texture analysis of the sea ice and processed at the freezer lab at the Norwegian Polar Institute. Texture was examined by first slicing ice samples very thin by use of a microtome. These thin ice slices were observed in polarized light that reveals the crystal structure of the ice. This data includes the photographs taken of the ice cores in natural light and in polarized light.