Iranian Granite Export
All rocks that are of internal or volcanic origin and must be processed by hard machines are known in the market as “granite”. Granite stone is very hard, strong, durable, rough, and polished, with a hardness of five to seven and has high compressive strength against weathering, has a variety of colors, and is resistant to frost.
The average volumetric mass in granite is about 2.6 tons per cubic meter. Its compressive strength is between one hundred and three hundred megapascals and its water absorption is usually less than one percent. Its porosity is very low and it shows good resistance against fire, but if water reaches it in the same condition, it will be severely damaged.
It has a seamless texture in appearance and is mostly found in gray, but it is seen in other colors such as pink
due to the presence of feldspars.
Granite stone could not be exploited and extracted as a plate until several years ago due to its high hardness, but with the advancement of materials science and the discussion of diamond technology and its application in this industry, the use of this stone has become significantly more common.
The best use of granite is when we want to use the high resistance of this stone against pressure, heat, cold and abrasion. For example, it is used as a cube in the dimensions of 10.10.10 or smaller and larger dimensions in a very high volume as a pavement in countries that have a very large minimum and maximum temperature difference. In Norway, the surface of many streets is covered with cubic granite or the use of this stone as an external curb and stairs (of course with a non-smooth surface) is very common in outdoor spaces. In the interior, the use of granite in the floor and body can be used due to its very long life and good resistance to abrasion. Of course, these benefits are most suitable for office and public buildings or in private buildings in public areas. It should be noted that in the use of granite in interior spaces, the subject of warm and cold colors and issues such as that are very much considered by architects and designers, is important and effective.
Granite stone with its various processing is used for all user spaces, including facades, stairs, public and private spaces, parking lots and open spaces.
In addition to the mentioned advantages, there are also defects or disadvantages on granite that we will deal with.
The characteristics that make choosing a stone from a designer’s point of view have two general aspects, one is fashion and the other is aesthetics and its combinations.
Granite in The Facade
Granite is one of the best choices because the facade of the building, especially in big cities, is directly related to climate change and pollution. When working with light colored granite in the facade, snow and rain water absorbed by the granite surface of the facade discolor the stone for a few days and the facade is seen as a stain. The cause of this phenomenon is water absorption in some parts of the rock and water loss in other parts of the rock, which does not happen in dark rocks.
Granite does not absorb the slurry well due to its hardness and low porosity and very low water absorption, and for this reason, there is usually not enough adhesion between the rock and the slurry. This causes the granite stones to fall on the facade. This problem of granite is solved by fastening and controlling granite stone to a large extent. If this is done by cracking the rock and tying it with galvanized wire before grouting, it is called a scoop. Another method is dry installation, which has different details and is very common today. At present, in Iran, the use of granite for facades is more fashionable than in previous years and they are used in new ways, but from the perspective of combined aesthetics, many architects still use it. In this case, the creativity of the architects plays the first role.
Granite Stone for Outdoor Floor
Granite is less used for open spaces in the form of polished because this stone is very slippery in this case and becomes dangerous if gets wet. The use of this stone in outdoor spaces such as sidewalks, streets, and yards in the polished form is not recommended at all. But it is very common in the form of uneven surfaces (hatchet, bush hammer, flamed, unpolished). Using this stone in such a way that it has a rough and uneven surface is one of the main applications of granite. It is also very common to use this stone to make all stone artifacts, benches, and sculptures for outdoor installation.
In cold areas where the depth of freezing is greater than usual, and mountain roads, as well as areas where there is a lot of runoff and of course the possibility of freezing, the use of granite cubic stone with its standard conditions and details increases. To install a cubic rock, the soil must be thoroughly pounded so that it does not settle in the future, and then complete drainage must be done to collect water after passing through the rock; It is like a grass stadium that can collect water from the surface and direct it from below during rain. After drainage, the cubic stone should be installed dry and the necessary care should be taken in picking it so that the pieces of stone are completely fastened together. After that, it is necessary to compact this installed surface and finally fill the joints between the stones with sand and a small amount of cement. In this case, the rocky surface will be fully usable for icy conditions and mountain roads. In addition, walking on this rock is medically very useful, such as walking in the forest and mountains. The famous Champs Elysees in France has seen such a level for many years.
The use of granite stone for the floor of the stairs, which should have a high resistance to abrasion and impact, is one of the best suggestions, but unfortunately, it is sometimes seen that 2 cm granite stone for the stairs has been chosen, the part of which is seen in front of the stairs. They can be attached with another 2 centimeter stone, which is called doubling.
This duplication process has several technical problems. These two attached stones get separated over time and create an ugly appearance. Meanwhile, the front part of the stair tread, which usually protrudes about 3 cm from the front of the stairs, is very prone to breakage. It is recommended to use at least one 3 cm stone or to double the 3 or 4 cm stone and attach these two parts together with wire.
Granite Color Change
Another issue that is said about granites is the issue of their color change, which we will discuss in the discussion of weathering in stone, but it can be said briefly, except for some granites such as Piranshahr Green Granite, where weathering leads to color change from green to yellow, the weathering process is common in rocks, and granites are almost less affected. Some granites contain iron oxides and sulfides, which react with air oxygen on the surface of the granite in the presence of air and are converted from one capacity to another or sulfurized to hydroxide. Sometimes this chemical reaction is accompanied by discoloration, in which case heat and moisture, as a catalyst, can help speed up the reaction, which leads to discoloration. Therefore, granite is prone to discoloration in different conditions and different times, depending on whether it is in the vicinity of high light (southern view) or low light (northern view) or indoor space away from the sun or in a humid or dry and cold area.
Today, the use of foreign granites is increasing rapidly due to economic issues. What is said to be a disadvantage of foreign granites, especially Chinese granite, is that these stones are painted and lose their color over time.
This claim is not true for all Chinese granite stones and only two or three samples of painted Chinese stone have been imported to Iran, which is also clear and the rest are not different from our stones, but some black stones by some sellers with black stone wax, become blacker. These stones can be tested by pouring hot water on the stone and creating friction on it several times. If this hot water darkens, it is clear that the stone is colored. When cutting stone with blue milling machines, the colored stones reveal themselves and usually color the returned water from the cutting. But natural rocks only cloud the water a little, which the water gets clear again as the particles subside.
Kian Karaman Aria Company with a brilliant history in foreign trade is one of the largest suppliers of goods in the field of trade of natural building stones including granite, travertine, marble, onyx, and crystal.
Contact our support and sales team for more information.