<p>Volcanic rock formations are rather common in relatively young volcanic regions such as in the Faroe Islands. The typical stratigraphic sequence is often formed by hard basalts intercalated with thin layers of scoria, breccias, and weak volcaniclastic horizons, i.e., red tuffs clearly presenting distinct mechanical and mineralogical properties. Upon excavation, ground behavior and tunnel stability can therefore vary significantly in relation to the rock formations encountered at the tunnel level. As such, empirical rock mass classification systems have been traditionally used in the Faroes for the assessment of rock masses and permanent rock support. However, this method can pose challenges, as important mineralogical and mechanical properties are not sufficiently characterized or accounted for in the tunnel support assessment. In this article, the properties of volcanic rocks in the Fámjin tunnel are investigated to find a basis for the study of ground behavior and tunnel stability in volcanic formations and ultimately to derive recommendations for optimal rock support design in similar ground conditions. For this purpose, a detailed investigation program and a comprehensive characterization of the involved volcanic rocks in the Fámjin tunnel were carried out to form the basis for elaborate numerical simulations. The results have revealed important limitations in empirically based rock support designs when compared to designs based on the application of more sophisticated methods and the detailed assessment of rock mass properties. On this basis, this study proposes a set of specific design recommendations that can contribute to more adequate tunnel support designs in layered volcanic rock masses.</p>