Types of igneous and sedimentary rocks:
Recrystallized marble (Chinese) Recrystallized Marble:
In a simple classification, rocks are divided into two parts: igneous-based rocks and sedimentary-based rocks. Igneous base rocks are placed in the vicinity of extremely intense heat of magma due to magmatic and volcanic operations and finally turned into stone. The most famous ones are andesite, basic, ultrabasic. The building samples available in the market are known as granite.
Sedimentary base rocks are the rocks that have turned into rocks after the sedimentation of previously eroded solutions on the sea floor and with the pressure of the sea due to the passage of time of all the deposited materials. Various elements and compounds are deposited on the sea floor, such as magnesite, calcium carbonate, and any other base that can be.
What types of stones are suitable for use in construction projects?
Stones that are used in construction projects for facades, floors, stairs and exterior spaces. They must have a series of features that we can use as building blocks.
- Its first feature is that we can cut into it and make it consumable
- Its second feature is malleability, which means that we can shape it and, for example, make solid objects
- The third feature is polishability that we can polish to make them beautiful
For example, andesite is not suitable for polishing and shaping and use in building. But granite at the base of igneous rocks and calcite at the base of sediments are stones that can be used in construction.
Types of calcite stones
Calcite, Caco3 or calcium carbonate in the sedimentary market are divided into several categories according to the conditions of formation, resistance, triaxial pressure tolerance and freezing test:
- Crystaled marble
- Crystals and porcelain (recrystallized) Recrystallized Marble
It is a weak and porous stone. It has tiny holes that absorb water and oil very high and is extremely weak and fragile. It gets damaged and contaminated quickly. It causes dandruff and is cheap. Due to its looseness, the cost of extraction is very low. For example, compared to porcelain stone, if one ton is extracted in one day. 12 tons of limestone are extracted in one day. Because its density is low, it puts very little pressure on mining machinery.
In general, it is not a good stone, but it is cheap. Due to its weaknesses, manufacturers have made changes to make it more usable. For example, they put a nano coating on it to raise its quality a little and lower its water absorption, but in the end it cannot be used much in the building and its use is directed towards carbonates and has industrial use. As a filler, it is used in water purification, it is used in the raw material of paper production, etc.
compared to limestone, it has different formation conditions. It has more resistance and strength than limestone. But they have big pores that are sometimes the size of knuckles. On the one hand, this void that causes the lightness of the stone is good. But on the other hand, the many holes make it look bad, so they fill it with resin, mastic, or other materials to improve its appearance. After it is filled with resin, mastic or other materials, it is sanded and polished to become a sensible stone.
Travertine is light and has a low density due to its large and numerous irregularities and is used for facades. But again, it is wrong to use it for facade because it has high water and oil absorption. This issue in cold weather causes that due to the freezing of water and liquids and its expansion in the holes of the stone, the stone is crushed and gradually destroyed. This process is called stone cancer or concrete cancer. With all the mentioned disadvantages, its beauty is its beauty, and if it is placed correctly, there is zero chance of falling off the facade.
Travertine is mostly produced in light and cream color spectrum and it has many fans due to the tendency to use light color in the facade of buildings. Many mistakes happen in the use of travertine.
for example: using it on the surface of the parking lot because of its beauty, which crumbles and disappears after a while.
Next, we will talk about marble, marble and crystal (Chinese) stones:
Generally, in the world, porcelain and marble are not distinguished from each other, and they are all called marble. In Iran and countries that produce stone, such as China and Turkey, porcelain and marble are completely separated. On the other hand, marble is also called Onyx.
Compared to travertine, marble has a higher density and the conditions of its formation are such that it has a more coherent texture, almost no pores and is a uniform stone. It has low water and oil absorption, but it has a higher price and its use is seen on the floor of the building and sometimes on the facade.
Another name given to marble is Onyx. This stone is very loose and does not have much quality. In terms of water and oil absorption, it has a very low level. It is weaker than all the stones except Limestone, but it has a special feature, which is that it allows light to pass through it. It has a luxury use, like a stone frame that is illuminated from behind this frame and has a beautiful effect. This stone is not supposed to be used in places where a load is placed on it. This causes it to have a high price because it is very difficult to process and it has earned the term super luxury. It has different colors, each of which is used somewhere, for example, its green color is used in the holy possibility, but the most expensive and rare one is blue marble.
Crystals or porcelain (we focus on the capabilities of this stone) Recrystallized Marble:
It has the highest quality among all these types of calcite, crystal or porcelain stones, which are also called metamorphic or metamorphosed stones. Another term used for this stone is crystallized and recrystallized stone, which will be discussed later. In metamorphic rocks, the process of transformation occurs due to heat and pressure, like sugar that turns into candy.
Chinese rocks have been in close proximity to ocean rocks and compounds and powerful heat engines over millions of years. The meaning of heat engines is the mass of magmas that in geology has caused heat and as a result the formation of interlocking rock crystals.
In this position, the small crystals of the stones are intertwined and these small crystals have formed larger crystals. In fact, the very high pressure and heat of the surrounding environment of these stones has strongly interwoven the texture of these types of stones. Its water and oil absorption is practically zero. It has very high strength, malleability and polishability, and it is extremely resistant to harsh environmental conditions. Therefore, based on clastic and sedimentary stones, the best stone to use in outdoor environments is crystal or porcelain stone.
With all the interpretations, we have marbles in the world that are better and more valuable than some Chinese ones, and that depends on the conditions of their formation over millions of years. In this situation, the physical and chemical analyzes that are performed on all kinds of stones and attention to the type of use of these stones in different places determine their value and quality.
The use of all kinds of stones in the world and in the countries of the Persian Gulf
In the Persian Gulf countries, if we want to talk about the materials used in the outdoor space or so-called out door, the biggest damage to the materials used in the outdoor environment, such as ordinary or reinforced concrete blocks or stones, is the harshness of the air. It is hot and humid with sometimes acidification due to industrial works. For example, Bandar Abbas, which is completely an industrial city, and this happens a lot in this city, but this problem has been solved by using porcelain stone instead of concrete tables.
If the concrete pavements of urban roads last 20 years in normal cities like Tehran, in Bandar Abbas and other Sharjah and warm cities of the Persian Gulf and the world, this will only last for 1 year, and these pavements must be replaced again. In the meantime, concrete street table manufacturers have thought of measures to make this type of concrete table durable and have invented a new solution for its more durable production. Such as polymer concretes, sulfocretes, sulfur concrete and methods that increase the durability of concrete.
Of course, every method that is mentioned increases the price of the product. For example, normal tables have a low cost, but to produce a sample of a table called Wet Press, the cost increases up to 4 times the production of normal concrete. In this method, concrete is poured into molds with special filters to remove the water. Then a press with a pressure of about 600 to 700 tons is applied on it, which makes all the voids disappear and the table is less damaged and creates a completely uniform surface. The use of cement in this type is equal to that of Table 3, so its price and weight increase a lot.
This has caused the competition of stone with advanced concrete blocks to increase because it is equal in terms of price.
Our Recrystallized Marble (Chinese) mines
There are rich mines in Iran that have a special type of high-quality Chinese and crystal stones, that is, they are a grade higher than Chinese and crystal stones. that is, they are a grade higher than porcelain and crystal stones. In the formation of the stones of these mines, all stages of sedimentation, pressure and magma and… It has been done on it. It turned into a stone and next to the thermal engines, the phenomenon of metamorphosis happened on it, and then due to some reasons, this stone mass in the heart of the sea came out of the water, which includes various reasons.
It can be due to the technological movement of the earth, like the Arabian subcontinent, it has moved under the Iranian plateau in this million years. This stone was moved and brought out from under the Persian Gulf, or due to the drying of the old ocean such as the Tethys Ocean, which created a large part of Iran today, or any other event that caused Chinese stones to form. In a special case, these Chinese stones may go to the bottom of the sea over millions of years due to natural factors such as earthquakes or technological movement, and once again all the described events will take place on them.
It means that the sediments, calcites, heat engines, etc. have an effect on them again, and once again they become rocks and metamorphose. These types of stones are called recrystallized metamorphic Chinese stones, the most famous of which is Bianco stone mine or Carrara stone mine in Italy, which has no credible history, but it is said to have a history of 2000 years of mining.
These types of Recrystallized Marble are so resistant that they have a remarkable resistance compared to granites.
Investigating the resistance of Recrystallized Marble (China) against acids
But granites have a unique feature that none of these sedimentary base stones have, and that is its very high resistance to acids. The base stones of clastics are corroded by acids, this is more evident in the field of using these stones in industrial environments where acid is likely to be used, and in the construction of kitchen counters. For example, if lime, which is acidic, is cut on this surface, if it is granite, nothing will happen to the stone. But if any of the stones are based on clastics, there will be a trace of corrosion in it. This applies to wine, vinegar, and coffee as well.
Analysis of Recrystallized Marble (China) against natural factors:
The method of analyzing stones is done in two physical and chemical ways. Chemical analysis is not very useful except in special environments and experts use more physical analysis, such as triaxial pressure tolerance, which is a physical analysis. or analysis of water absorption, oil, freezing test, etc. Depending on the customer’s needs, a series of tests and analyzes may be done on the stones, which is mostly done in large projects. One of the famous tests for wear resistance is the Los Angeles wear test, which is performed on stones. This test is suitable for using stone for high-traffic areas such as church entrances and sidewalks that are exposed to high traffic.
Another testing method to ensure the quality of the used stone is to pour liquid wax on the stone. If the stone used is Chinese marble or granite, no wax will remain on it, while other stones quickly absorb water, oil, or other types of environmental dirt.
Conclusion about the use of Recrystallized Marble (China).
In the meantime, it should be noted that when comparing the price and quality of granite and porcelain, medium quality granites may cost more than the more expensive crystal and porcelain stones. On the other hand, the use of cheap granites with minimum price and quality in some projects in the long run may cause a lot of costs for the employer and the contractor.
Another special feature of recrystallized porcelain stone is that it is naturally formed in a warm region, and this issue is important for the countries of the Persian Gulf because it is very resistant to heat.
In general, porcelain stone or recrystallized stone is very suitable and cost-effective for use both in the open space outside and in damaged spaces inside. Pay attention to the fact that transporting these stones from distant countries such as China is not economical, because to transport each one-meter stone with a weight of about 50 to 60 kilos, 2 dollars should be paid for transportation. While if you get these stones from the Persian Gulf area, the cost of transporting them is completely negligible.
For example, in a two-kilometer street that has a boulevard in the middle and two streets on the sides, we need about 12 kilometers of tables, which will only save about 12,000 x 2 x 24,000 dollars.