By Chisom Ibemere
Anorthosite is a type of intrusive igneous rock which consists of plagioclase feldspar minerals. It was described initially in 1815 and named by a German mineralogist, Abraham Gottlob Werner.
Its name was gotten from the Greek words “an-” meaning without and “orthos” or straight. It also refers to the lack of orthoclase feldspar typically found in other granitic rocks.
Anorthosite is commonly found in large, intrusive bodies known as anorthosite massifs. It forms when molten magma with high content of plagioclase feldspar, solidifies deep within the Earth’s crust. Anorthosite can be discovered in various regions worldwide such as Norway, Canada, Greenland, the United States, and South Africa.
Anorthosite possesses a unique appearance with its predominantly light-colored feldspar minerals, making it a desirable material for decorative purposes.
It is often used as a dimension stone in building and construction projects, like countertops, flooring, and wall claddings. It is also used in the manufacturing of high-quality ceramics or used as an aggregate in road construction.
Anorthosite massifs often contain valuable minerals and ores associated with the igneous processes involved in their formation, such as titanium and related minerals. These minerals can provide economic value and mining opportunities in regions where anorthosite is present.
Anorthosite is composed of mainly calcium-rich plagioclase.
It has light colors, such as white, gray, or reddish-brown. It has a coarse-grained texture and it’s durable.
The global value of anorthosite lies predominantly in its utility as a building material. Its unique appearance, strength, and ability to take a high polish makes it a sought-after stone for architectural and decorative applications.