Difference Between Basalt and Granite

Basalt vs Granite

Earth is made up of three kinds of rocks namely igneous rocks, sedimentary rocks, and metamorphic rocks. Basalt and granite are two types of igneous rocks. All rocks of igneous origin are made up of magma or molten earth that finds its way up to the surface of the earth from fissures and cracks underneath the surface of earth. The molten rocks that come out in the form of lava, upon cooling takes shape of igneous rocks. Two of the most famous igneous rocks, basalt and granite have similarities causing confusion among people. However, there are many differences between basalt and granite that will be discussed in this article.

Of the two, basalt is darker and consists of fine grained minerals such as magnesium and iron. Basalt rocks are also called mafic rocks just because of this property. Those who know the symbols of magnesium (Mg) and iron (Fe) will easily understand the logic behind the word mafic rocks. Granite, on the other hand, is lighter in complexion and has a coarse grained texture. These rocks are found at depth and are seen only when deep erosion takes place. Granite has a different composition as it is mostly made up of feldspar and quartz, and hence, the name felsic rock. Among other differences, the nature of these rocks reveals that basalt is basic in nature, whereas granite is acidic in nature. Basalt is formed when magma cools and solidifies on the surface of the earth. It is mainly found on the floor of the ocean as magma solidifies quickly coming in contact with cool ocean water. On the other hand, granite is found above ocean and makes up much of continental crust.

Basalt is an extrusive igneous rock, whereas granite is an intrusive ingenuous rock. Those who do not know, extrusive rocks are those formed of lava coming out of volcanoes, whereas rocks formed of magma that has yet not come out of the volcano are termed as intrusive rocks. Cooling of intrusive rocks takes much longer than extrusive rocks as they are under the surface of earth. One other difference pertains to the way these two types of rocks split when put under pressure. While basalt rocks split along columnar planes, granite rocks give way along horizontal planes. Obviously this difference exists because of differences in the way the two types of rocks cool down.

What is the difference between Basalt and Granite?

• Basalt is mostly found on ocean floors, while granite is the crust of earth in all continents.

• Basalt is extrusive, while granite is intrusive igneous rock.

• Basalt is darker and is composed of magnesium and iron, whereas granite is lighter and is made up of feldspar and quartz.

• Basalt is called mafic, while granite is called felsic.

• Basalt splits along columnar planes, while granite splits along horizontal planes.