Description
Basalt underlies more of Earth's surface than any other rock type. Most areas within the Earth's ocean basins are underlain by basalt. Although basalt is much less common on continents, lava flows and flood basalts underlie several percent of Earth's land surface. Basalt is a very important rock.
Basalt is also an abundant rock on the Moon. Much of the Moon's surface is underlain by basaltic lava flows and flood basalts. Olympus Mons is a shield volcano on Mars. It, like most other volcanic features on Mars, was formed from basaltic lava flows. It is the highest mountain on Mars and is the largest known volcano in our solar system.
Uses
Basalt is used for a wide variety of purposes. It is most commonly crushed for use as an aggregate in construction projects, road base, concrete aggregate, asphalt pavement aggregate, railroad ballast, filter stone in drain fields and many other purposes. Basalt is also cut into dimension stone. Thin slabs of basalt are cut and sometimes polished for use as floor tiles, building veneer, monuments, and other stone objects.
Source: https://geology.com/rocks/basalt.shtml