Black stones are typically igneous or metamorphic rocks that appear dark in color due to their mineral composition. Common examples include basalt, obsidian, and slate. These stones are often used in construction, landscaping, and decorative applications due to their durability and aesthetic appeal. In geology, black stones can indicate volcanic activity or the presence of certain minerals like magnetite or pyroxene. They can also be found in various natural settings, such as riverbeds or mountainous regions, where erosion exposes their surfaces. Their unique properties make them significant in both natural and human-made environments.