basalt

The dark grey basaltic rock is the most abundant rock on Earth. It forms the bedrock of almost all oceans. This extraordinary rock extends beyond our planet, with deposits discovered on the Moon, Venus, Mars, and even several known asteroids. The crust of numerous planets consists predominantly of basalt. Olympus Mons, the tallest volcano in the solar system, is a colossal mass of basalt standing at 25 km in height and with a diameter of 600 km. You can observe it through a telescope when looking at Mars.

The Latin name for basalt signifies a highly durable stone. The hardness of this natural stone rivals that of granite and can even surpass it. Basalt is a relatively young rock, with no oceanic crust older than 200 million years beneath Earth's oceans. It continues to form in various underwater locations. Romans utilized basalt to construct houses, temples, stadiums, and paved streets. Today, this exceptional and intergalactic stone can grace your home as a worktop, window sill, or fireplace surround.

With a durability comparable to granite, basalt proves to be an excellent construction material. Beyond its strength, it serves as an outstanding thermal insulator, with insulation parameters several times higher than those of other stones and construction materials. Environmentally friendly, non-toxic, non-explosive, and non-flammable, basalt also boasts a slip-resistant surface. This high-quality stone is extensively used in construction and decoration, covering applications such as street paving, terrace and floor construction, countertop fabrication, as well as wall panels and fireplace surrounds.

Noteworthy beyond our planet, basalt forms the highest mountain on Mars. On Earth, it is renowned for playing a role in crafting mysterious ancient world monuments. The iconic giant heads of the Moai sculptures on Easter Island are primarily carved from basalt. Additionally, the Rosetta Stone, a crucial artifact for interpreting Egyptian hieroglyphs, is crafted from basalt.

Extensive layers of basalt are situated beneath the Earth's oceans. Basalt forms where the Earth's crust fractures, and the volcanic magma that emerges cools rapidly. Such rocks are referred to as effusive. The majority of basalt forms at the boundaries of separating tectonic plates, which are the thinnest areas where convective currents in the Earth's interior bring hot liquid rocks from the lower mantle. When a gap opens between the plates, magma surges up and spills onto the ocean floor. This process resembles a gaping wound bleeding until the cooling basalt creates a clot. These clotted formations on the ocean floor extend for thousands of kilometers, contributing to the creation of new seabed.

On continents, basalt is only present where Earth's forces push the seabed inland or when lava spills out during the separation of continental plates. The latter occurrence is much less frequent on continents compared to oceans. Typically, most of the ocean floor consists of basalt, while most continents are granitic. Due to its higher density, basalt, which is heavier than granite, tends to sink. In simple terms, the basaltic crust is heavy, and the granitic crust is light. Consequently, the granitic continents float on the basalt, resembling lumps of solidified foam.

Basaltic magma solidifies rapidly, whether in water or on the surface, preventing the minerals within it from growing large, as seen in coarse-grained rocks like granite. This quick cooling process results in an almost invisible, fine-grained structure of the rock. Some basalts are glassy, many are fine-grained and compact, but most exhibit a spongy texture. The small cavities formed by lava vapor are often filled with secondary minerals such as calcite, chlorite, and zeolites.

The color of basalt varies based on local geology, with basalt generally rich in iron and magnesium. Its high content of magnesium oxide and calcium oxide, combined with low levels of lighter silicate minerals, gives basalt its characteristic black color. Occasionally, iron ore compounds may impart a slight brown or orange hue to basalt slabs. While basalt is typically grey to black, its color can shift to brown or reddish due to the oxidation of iron-rich minerals into rust. Basalt registers a hardness of 7 on the Mohs scale.

Basalt constitutes a significant portion of the Earth's surface, although it is less common on continents. Typically, it is found beneath the oceans where the Earth's crust is thinner. The ocean floor is predominantly composed of basalt. Notably, basalt offers a heat insulation value three times higher than asbestos, without posing any toxic hazards. Basalts primarily consist of magnesium oxide (MgO) and calcium oxide (CaO), with a low silicon (SiO2) content, usually less than 50 percent. They also contain iron oxide (FeO) and aluminum oxide (Al2O3).

Quarried in various locations globally, basalt is a prevalent and widely occurring volcanic rock. Basalt quarries are present in the US, specifically in the states of Washington, Oregon, and Idaho. European countries such as Italy, Germany, and the United Kingdom also have basalt quarries. In Asia, basalt is quarried in India and China, while Africa has basalt quarries in South Africa and Ethiopia. Brazil is a prominent source of South American basalt. South American basalt mainly comes from Brazil.

Basalt is typically extracted from quarries located on the Earth's surface. The process involves creating long lines of parallel deep holes in the bedrock using specialized machines equipped with powerful drills. After the holes are drilled, wedges are inserted and hammered into the openings to separate the large square blocks. Subsequently, these basalt blocks are further processed into slabs and transported to workshops for fabrication. Basalt chips are obtained by crushing the quarry slopes with crushing machines. Basalt blocks can also be split as this:

It is advisable to seal basalt for enhanced stain resistance and ease of maintenance. Basalt, being porous, can readily absorb moisture, dirt, and glue if left unsealed in a quarry or fabrication workshop. This absorption may lead to the leaching of minerals and salts over time, resulting in the stone turning pale blue or cloudy. Unfortunately, once this occurs, there is no chemical or specific cleaner capable of removing stains from the stone. At times, basalt tile surfaces may be stained with mortar, causing an uneven and blotchy appearance. Although chemical cleaners can eliminate surface grout, they may prove ineffective if the grout has penetrated the open pores. In such cases, scrubbing efforts will likely yield little improvement. Moreover, applying additional sealing may only accentuate the marks left by adhesives and mortars.