Q. Is basalt a natural stone?

Anyone may find basalt on both the moon and Earth making it one of the few natural stones with a truly global distribution. Over time volcanic eruption and cooling produced the most common rock in the Earth's crust. Basalt is a frequent type of extrusive volcanic rock that is typically gray to black in color and fine-grained as a result of the rapid cooling of lava on the surface of a planet. With a SiO2 content between 45% and 52% and mostly consisting of basic plagioclase and monoclase pyroxene trailed by orthopyroxene peridot and amphibole basalt is the most widely disseminated basic extrusive rock.