Learn About Basalt

What is Basalt?

Basalt is a fine-grained igneous rock of dark colouring, due to its high magnesium and calcium oxide content. It is formed when basaltic lava comes in contact with the Earth's surface. It is then known as an extrusive rock, which then cools, hardens and forms crystals over the next few days or weeks, which is how we see it today.

What is Basalt used for?

Basalt is mainly used for structural building materials such as bricks, tiles, foundations and sculptures, as well as within stonewalls for thermal purposes and rail tracks. It can also be seen when looking at the moon as darker area which were formed from ancient lava flows.

Why is Basalt of interest?

Basalt is very strong and dense, meaning that a lot of the stone is used in construction. Crushed basalt is often used for the base of pavements and roads, in concrete as well as in the filtration of drainage. In construction, large slabs of Basalt can be used as tiles and bricks.

Basalt fibre is a material made from extremely fine fibres of basalt. It is similar to fibreglass having better mechanical properties than fibreglass, but being significantly cheaper than carbon fibre. It can be used to make blades for wind turbines.

The rock also has excellent thermal and friction properties which means that it works well as an insulator, as well as worktops and around fireplaces. It is often used as a replacement for asbestos, in order to protect people from its toxic effects.

Interesting Facts About Basalt

Many lunar Basalts were collected during missions to the moon whereby it was discovered that due to the lack of exposure to oxygen, they are less prone to oxidisation than those found on Earth. When looking at the moon we often see darker areas which are known as “lunar maria,” which are as a result of extensive basalt flows. The largest volcano in our Solar System, Olympus Mons, is also formed completely by basaltic flows.