Is basalt impermiable

Basalt is generally considered to be relatively impermeable compared to other rock types, especially when it is fresh and unaltered. However, it can have varying degrees of permeability depending on its structure, mineral content, and the presence of fractures or vesicles. In some cases, basalt can allow the movement of fluids through these features, although it is still less permeable than sedimentary rocks like sandstone. Overall, while not completely impermeable, basalt tends to limit fluid flow more effectively than many other geological formations.