What is granite?

Granite is derived from the word "granum" and is usually composed of quartz, mica, feldspar. The texture of this stone is in the form of grains that these grains may sometimes be microscopic and sometimes their dimensions reach even a few centimeters and a few meters. This rock is usually formed in the Earth's crust due to the cooling of molten material, but the cooling process of these rocks is slow and for this reason we see a special hand in their grain texture and like other volcanic rocks We do not see them as sponges.

Granite and its types

In general, granite is observed and classified into three categories. Granite rocks that were formed about two million years ago, which is called the pre-geological period, were formed. These stones can not be used as decorative stones because they were formed during the Earth's orogeny.

In principle, the granites that are used for building work and are aesthetically valuable are related to the Mesozoic and Cenozoic periods in geology. Since granite rocks have different appearance depending on the time and conditions and place of their formation. , The main color that is considered for it is the color of its paste or in other words the color of the majority of its elements.

What are the elements of granite?
The chemical composition of granites consists mostly of silicon and aluminum, which make up about 85% of the composition of granites, and the remaining 15% are elements such as: titanium, iron, calcium, magnesium, sodium and potassium.

The main minerals forming granite
Granite is composed of the main minerals which are: quartz, plagioclase, potassium feldspar and other dark minerals. The amount of these minerals in granite determines the name of granite rocks. Also, sometimes other minerals such as pyrite, hematite, mannite and ilmenite are found in granite rocks. In the following, we will explain the granites that have been identified with other names due to the presence of more or less percentage of minerals. :

Granophytic granite rocks: This type of granite has fine grains of crystals that are made of quartz and feldspar that these fine grains have grown inside each other and have formed this type of granite.

Aplite granite rocks: This type of granite is composed only of quartz and feldspar and is likely to be a very small amount of mafic minerals, the texture of this granite is called apilite.

Pegmatite granite rocks: This type of granite has a coarse grain texture.

Of course, it must be said that some granites may be metallic minerals such as mercury, manganese, magnetite, copper, gold and silver.

Granite rocks and their texture
The texture of granites is granular and these grains are spread from medium to large on the surface of granite rocks and are usually semi-shaped. (That is, they appear to be in a state of existence and disappearance). Coarse grains of potassium feldspar crystals are found in granites called porphyry textures.

Also, in some granites, very fine minerals such as apatite and sphene are found in very small sizes. Of course, there is another category for the texture of granites, which is called block, mass and rubble, as well as one of the textures. Very common in granites Granular texture that this type of texture can be seen in the form of fine to large grains in ceramics.