Veins are common structures in rocks and occur in different geological settings ranging from continental to oceanic crustal environments. They form by mineral precipitation from a fluid phase within a dilatational site or due to displacive mineral growth. Veins may form under a range of temperatures and pressures and precipitate from fluids of different origin. As a result, vein structures and microtextures as well as mineralogical, elemental, and isotopic compositions vary depending on the geological environment and local to regional physicochemical conditions. Therefore, veins are ubiquitous structures in the geological record and represent an insightful geological material and tool to answer diverse research questions. In previous studies, vein microtextures and geochemical compositions of vein minerals have been widely used to reconstruct kinematic histories of rocks and to quantify the physicochemical conditions under which veins formed, respectively. Thus, this session invites contributions from structural geology using veins as stress and strain indicators, geochemical studies investigating elemental and isotopic vein mineral compositions such as fluid-rock interactions, laboratory as well as numerical experiments simulating natural vein microtextures, and applied geosciences dealing with ore mineralization hosted in veins.