Black basalt

 We have black basalt, grey basalt etc, which are mostly used for building construction use, like G684 Black basalt, Mogonia black, and ZP Black.
And also some basalts are with many air holes inside, we often called them lava, like grey lava, red lava etc, which are widely used in the garden landscape, or for red lava, it is famous to be used as filter material.