What is basalt stone? Basalt stone is an igneous and volcanic rock formed when basaltic lava is exposed on the surface of the planet (think of a volcano erupting and lava oozing) that cools very quickly and hardens into rock. Basalt is often compared to granite since both stones are igneous rocks. Both of these stones mostly do not contain calcium carbonate and typically do not react to acids. It is this bit of information that makes basalt a great choice for installations in homes and buildings. Are you looking for basalt stone suppliers from China?Welcome to contact us.