Q. What is the color of basalt stone?

Answer

Due to the presence of augite or other dark-colored pyroxene minerals, basalt is typically a dark grey to black in color, but it can come in a wide variety of tones. Rapid cooling of basaltic lava, which is similar to gabbro-norite magma, occurs when magma from deep inside the Earth's crust is exposed at or near the surface. There are very few gas voids in these widespread and thick basalt flows. The size of the shown specimen is roughly five centimeters, or two inches.