Many people thinks that stone is a runty thing; but truth is stone have been used in all years that humankind existed. But today, the use of stones has gone beyond the role of primary tools and has taken on a decorative role. Granite is one of the stones that has many uses in decorating buildings.
Granite is one of the stones that is widely used in the construction industry and interior and exterior design of buildings. The word granite has its roots in French, but in Iran its ancient name is “khara”. This rock is a type of igneous rocks, which has an acidic content. In fact, granite is formed by cooling the masses of acidic molten material. The most important reason for medium and large grains in the texture of this rock is related to these masses of molten material. This rock contains mica, feldspar, quartz and some minerals in the same cooled molten material.
Estimating granite stone
Granite is known as a symbol of hardness and strength. This rock has a high density due to its low porosity, and is considered as one of the heavy rocks. The density of granite is 2.75 grams per cubic centimeter. The range of colors of granite includes white, gray, green and pink.
An important feature of this stone is its high corrosion resistance, which has become a practical tool in laboratories. The special beauty and variety of colors in this stone, along with its high resistance, causes frequent uses in urban planning. Another feature of stone is that it looks more uniform and harder than limestone. Heat resistance has caused this stone to be used in furnaces as well.
Advantages of granite
- Very high strength and hardness
- Variety in design and color
- Compatibility with other materials (metal, wood, glass)
- Corrosion resistance
- Water resistance
- Abrasion and scratch resistance
- High heat and temperature resistance
Disadvantages of granite
- Very high weight and density
- Not suitable for building insulation
- It takes a long time to adhere to the mortar, which is useless and dangerous
The cost of processing and extracting this stone also depends on the region and its geography. Due to the high hardness of granite, its cutting and preparation costs are much higher than limestone. Of course, for this reason, it has a much higher durability and longevity than limestone. Another component of the pricing of this stone is directly related to its dimensions. Of course, the amount of use that this stone has makes people willing to do it as well as costs
Colors of granite
There are many minerals and elements in granite. These elements and minerals have been frozen in the negotiating masses. They have created different colors in the background of these stones. We take:
- Quartz (milky white)
- Feldspar (white)
- Potassium feldspar (pink)
- Biotite (dark brown or black)
- Muscovite (gold or yellow)
- Amphibole (black or dark green)
There is no granite with 100% black color and it is not granite at all. Quartz in granite rocks causes it to whiten (even in small amounts). Granite is a black hand called gabbro. Gabro is also made of igneous rock, but its raw materials are different from granite.
There is no 100% white granite, and it is artificially made. The white cause of this model of granites is also due to quartz (milky white) and feldspar (matte white). The presence of black spots in these rocks also indicates the presence of amphiboles.
White and black granite
This granite is of equal amounts of amphibole, quartz and feldspar, which causes black and white hollow granite. The most use of this stone is in the kitchen and work table.
Pink granite has large amounts of potassium feldspar, and is one of the main ingredients in this paint. Of course, there are other minerals in the rock, such as feldspar, quartz and amphibole, which produce matte white, clear milky grains and brown or black.
The presence of some grains of iron ore and iron oxide, as well as in some cases associated with feldspar, also causes redness of granite. In a simpler example, it is like rusting iron, which turns red.
Note: There are other colors of granite on the market that we do not deny. They are usually from other igneous rocks, known as granite. But in principle, they have nothing in common in terms of structure and ingredients with granite.