"Volcanic basalt" refers to a type of rock that is formed from solidified lava that comes out of a volcano. It has a dark color and a porous texture. Full definition
According to Oddity Central, the restaurant's customized grill was a bit of an architectural feat: in order to bypass the problem of not being able to build conventional foundations due to the heat underground, architects Eduardo Caceres and Jesus Soto used nine layers of volcanic basalt rock to make a suitable cooking pit. (treehugger.com)
Because it was his, because it represented so much of what was cool about New Zealand in general, because it sat in the middle of the most stunning slice of Pacific Rim scenery, all green hills running to the sea and waves breaking on black volcanic basalt. (sbnation.com)
Hallis previously used hydrogen isotope ratios in volcanic basalt rocks to conclude that Earth's water may in fact have been part of the very dust cloud from which the planet first condensed. (newscientist.com)