An introduction to granite rocks

Granites are a type of felsic, intrusive, and igneous rocks that are widely found. The texture of granite is medium to coarse, rarely with a few crystals larger than the rock that forms the soil mass called porphyry. Granites are found in different colors such as pink, dark grey, green, yellow, red, or sometimes even black and gold, depending on their mineralogy and chemistry. Sometimes the granites are found in circular depressions surrounded by a series of hills formed by metamorphic hornfels. Granites are often massive and lack internal structures. They are hard, hard and their use for construction purposes has become widespread. 2.75 g/cm3 is the average density of granite. If you look at the word ‘granite’, it comes from the Latin word ‘granum’ which is a grain, referring to its coarse-grained constitution.

According to a scientific diagram, granites are classified into coarse-grained plutonic rocks – granitoids and are named according to the percentage of quartz, alkali feldspar – sanidine, orthoclase or microcline. Granite-like rocks that are silica under saturation may have a feldspathoid such as nepheline. According to modern petrology, true granite contains alkali feldspars and plagioclase. When a granitoid is devoid of or nearly devoid of plagioclase, the rock is said to be alkaline granite. If the granitoid contains less than 10% orthoclase, then it is called a tonalite. Amphibole and pyroxene are of common hue. Granites that have biotite and muscovite micas are called two-mica or binary granite. Two-mica granites are generally low in plagioclase and high in potassium; Type A or Type S granites. Rhyolite is a volcanic equivalent of plutonic granite.

Earth is currently the only place where granites are known to form a major part of the continental crust. Granites often occur as relatively small, less than 100 km² stock masses, and also in batholiths that are associated with orogenic mountain ranges. Smaller dikes of granite compositions are known as aplites and are often linked with margins of granite intrusions. In some places, along with the granites, masses of very coarse-grained pegmatites occur. Granites have been introduced into the Earth’s crust during all geological periods, such as earthquakes, although most have occurred in the Precambrian era. Granite rocks are widely distributed throughout the Earth’s continental crust, and it is the most abundant basement rocks that underlie the relatively thin sedimentary layer of the continents.

Despite being quite common around the world, the places with the most commercial granite quarries are in Norway, Sweden: Bohuslän, Finland, northern Portugal in Chaves, Spain, mainly in Galicia and Extremadura, India, Brazil and several other southern African countries. such as Angola, Namibia, South Africa and Zimbabwe. Today, granites are widely used in the manufacture of luxury flooring, kitchen tables, office tables, bathrooms, and bathtubs.

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