Let's look into the pantries of the Earth. What is granite and what is it made of? Varieties of granite in nature and their names
Do you know that all materials on Earth rest on powerful granite slabs? Granite is a hard rock that is one of the main materials that form the outer part of the earth's crust.
The name "granite" comes from the word "granum", meaning "grain" in translation. This, however, as you understand, is not about grains of wheat or rye. Grains are called crystals of quartz, mica, feldspar, hornblende and other minerals that are constituents of granite. Granite color may vary. Most often it has a grayish or pinkish color, but the presence of impurities in it can change its color.
Granite is a volcanic rock. As a rule, it is formed in the depths of the Earth when molten magma cools. Magma is a mixture of various minerals that looks like dough.
Granite is formed in mountainous regions. Rocks on the surface of the Earth, like a huge blanket, prevent magma from cooling too quickly. Granite is outside only when the outer covers are "weathered", that is, they are destroyed under the influence of water, wind, ice, or as a result of movements in the earth's crust, when granite blocks are pushed to the surface.
After that, however, the granite itself undergoes weathering. The feldspar crystals are destroyed first, turning into a mixture of clay and salts. Only quartz is able to resist the influence of the forces of nature. Over time, only fragments and mineral dust remain from the giant granite rocks, which, together with the remains of living organisms, form the soil.
Granite is one of the most durable building materials. He goes to the construction of facades of large buildings, monuments, as well as the manufacture of gravestones and tombstones. The ancient Egyptians used it to build temples and the famous pyramids.
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Part granite also includes quartz. White sands are pure quartz. Plain sand is also mostly quartz!
Granite, as a rule, has a granular structure: from fine to coarse-grained
Granite is a complex natural stone. Mainly formed from feldspars, mica and quartz
NAME
Granite (from lat. granum - grain)
COLOR
Depending on the proportional combination of minerals, it acquires different colors. It has a rich color range: from black - to the traditional red-burgundy with black - to white with gray.
By the way, it is feldspar and quartz that create the “spotted” effect.
Granite is coarse-grained, medium-grained and fine-grained. This amazing stone has a rich color range, from the traditional red-burgundy version with black flecks to white with gray blotches (and vice versa).
The most common granites are gray ("Siberian", Gray Quenna) and black (Absolute Black, Nero Africa), but there are also rocks of pink-red (Rosso Marina), white ("Mansurovsky"), yellow ("Zhiltau") and green ( Forest Green) tones.
PLACE OF BIRTH
Granites are a widespread rock found on all continents of our planet.
In the United States, granites are distributed along the coast of the Atlantic Ocean (from Maine in the north to Georgia in the south), they form large massifs in the north of the country, in the central part of the Ozark plateau, in the Black Hills and the Front Range of the Rocky Mountains.
In Russia, about 50 deposits of granite suitable for use as piece stone, as well as rubble and crushed stone, are known - on the Karelian Isthmus, in the Onezhye and Ladoga Regions, the Arkhangelsk and Voronezh Regions, in the Urals, in Primorye and Khabarovsk Territory, Eastern Transbaikalia.
A large granite deposit is located in Ukraine. Across the entire territory of the country, from the northwest to the southeast, the Ukrainian crystalline shield stretches. The width of its part, directly coming to the surface, is 200 km, and the length is about 1000 km. It is on this strip that the main deposits of decorative stone are concentrated.
QUALITIES
1.Durability. The best varieties of fine-grained granite begin to show the first signs of destruction after more than 500 years, so it is often called the "eternal" stone;
2.Strength. Granite is highly resistant to friction, compression and abrasion. It is a very dense (2.6-2.7 t / m³) and durable stone (its compressive strength is 90-250 MPa - twice that of marble);
3.Resistant to weathering and acids. Granite is an ideal stone for exterior decoration of buildings.
4.Waterproof. Granite practically does not absorb moisture (water absorption coefficient - 0.05-0.17%). That is why granite is perfect for facing embankments.
5.Environmental friendliness. Contrary to current prejudices, the natural radiation level of most granites corresponds to the 1st class - i.e. they are radiation safe and suitable for all types of construction without restrictions;
6. Wealth of textures. Unpolished, rough stone that absorbs light; polished to a mirror shine, showing the world a unique light play of mica inclusions - the decorative possibilities of granite are able to satisfy even the most complex design ideas;
7. Compatibility with other materials. Granite goes well with wood, metal, ceramics and other materials used in modern construction. It will "fit" into any interior - from classic to ultra-modern;
8. Rich color palette. The most common is gray granite, but there are also red, pink, orange, bluish-gray, bluish-green.
APPLICATION
In modern construction, granite is used so widely that, without exaggeration, it can be called a universal material.
Floors, stairs. Granite is a material with a very low level of abrasion. Even if 1 million people walk up the stairs in your personal apartment in a year, they will be able to erase its steps by no more than 0.12 mm;
Various interior details. Window sills, cornices, skirting boards, railings, furniture tops, coffee tables, bar counters, balusters, columns - the high strength of granite will allow these items to remain intact for many years, to avoid mechanical damage due to temperature and humidity;
Facade and interior decoration. Granite is a very ergonomic material that can provide you with a comfortable stay in a building;
Elements of landscape design. Alpine hills, rockeries, Japanese gardens, decorative ponds - made of granite, these fashionable compositions will give your garden naturalness and originality.
Borders, steps, paving stones for pavements. Granite is successfully used in places where more "endurance" is needed. It is resistant to mechanical stress, chemical pollution and temperature changes - it does not change its properties during hundreds of freezing and thawing cycles.
Embankment lining. Granite practically does not absorb moisture - accordingly, when the temperature drops, additional internal pressure from frozen water does not form in the pores of the stone, which can lead to the formation of cracks and destruction of the rock.
Granite paving stone. The use of granite paving stones dates back thousands of years. The famous ancient Roman cobbled roads can still be walked today; paved streets, you will find in the old part of any of the European capitals; in modern cities, stone roads are gradually replacing asphalt and concrete.
MAGICAL AND HEALING PROPERTIES
Ever since primitive times, man has been accustomed to trust the stone. This natural, living, "feeling" material will relieve psychological stress, bring coziness, tranquility and comfort to your home.
Have you ever thought about the origin of the expression "nibble on the granite of science"? Why, speaking of diligent and capable students, do we remember exactly granite, and not any other stone? It turns out there is an explanation for this. According to some observations, granite has the ability to stimulate human mental activity, helping to achieve success in scientific research.
This is a natural stone. It is mined in many places on our planet and it is likely that it is not found on other planets in the solar system. Therefore, it is granite in various sources that is called the "calling card of the Earth." This is one of the most durable breeds in the world. The composition of granite includes most of the known minerals: feldspar, quartz, as well as mica formations of various origins.
Is granite a mineral or a rock? This question is often asked by people who are just beginning to be interested in geology and mineralogy. In essence, it is a rock. As already mentioned, it includes various minerals, and its composition is heterogeneous, in contrast to minerals (for example, quartz, amethyst, chrysolite), which are uniform in both structure and color.
Rock granite is widespread in our life everywhere: in the form of railway embankments, tombstones, wall cladding, street elements of decorated decorations. Granite products have long been presented to people as the most ordinary and familiar to the eye. Often we just pass by without focusing on how different this amazing stone can be. Those who wish can get to know him better: after all, few people think about what granite consists of and what is the history of its occurrence.
How did granite come about?
It is generally accepted that there are two natural ways in which this natural stone was formed. It could arise from melted magma (solidified volcanic lava). In the depths of the earth's crust, magma slowly cools, turns into a petrified structure, in which grains of granite rock, having different sizes, crystallize for millions of years. It is no coincidence that its name itself comes from the Latin word "granum", which means "grain".
Natural stone granite is formed in nature in a different way. Sedimentary rock, as well as clay-like sand and heterogeneous stones, were gradually displaced by tectonic processes into the depths of the earth's crust. There, under the influence of high temperatures and pressure, substances melted and a process such as granitization.
Most of all, the formation of granite occurs in the so-called places of collision. Two continental plates collide with each other, which causes an increase in the layer of crust on the continent. Many scientists believe that it is as a result of the thickening of the collisional layers of the crust that layers of granite melt appear - at a depth of 10 to 20 km. This phenomenon has been named granitic magmatism . It is most typical for the Andean batholiths, as well as for island arcs.
Where are the granite deposits
The main place where granite occurs is batholith mountain ranges, the length of which is about 4 km, and the area is several hectares. Sometimes during mining it is seen that several layers of stone have formed: granite and its sedimentary rock. The stone itself looks like wide layers, alternating with representatives of sedimentary and metamorphic species.
Like other minerals, which are not very rare, granite has become widespread almost everywhere: it can be found on any continent . Due to the fact that over the course of millions of years, ancient rocks gradually forced younger formations upward, it came to the surface and became available for mining.
Chemical and mineralogical composition
As already mentioned, granite is a stone that has a granular structure in the form of crystals. The chemical formula of granite is represented by such basic elements as iron, calcium, magnesium and various alkalis.
Its main components are quartz, dark-colored formation minerals and feldspar. Spar provides certain shades, and if there is a lot of translucent grain in the stone, it means that it contains a lot of quartz.
Depending on what rocks are included in a particular stone, the mineralogical composition of granite can be different. For example, if it is dominated by plagioclase and there is little feldspar, it is called plagigranite. If, on the contrary, there is more feldspar in the stone, and less dark colors, this alasquite.
The chemical composition of the rock has the following scheme:
- content feldspars(orthoclase and plagioclase) - from 60 to 65%;
- quartz, providing high strength indicators - from 25 to 30%;
- mafic minerals granite - from 5 to 10% (mostly biotites).
Depending on which feldspars are part of the stone, its color will also change. The most common is gray, on which different shades can appear: blue, pinkish, red, less often - greenish. Coloring also depends on what is included in the composition of granite from dark-colored minerals. If the seekers come across a rock consisting of biotite or hornblende, the stone will be painted in dark colors. There is a rather rare species called Yantsevsky, which has a pronounced shade of greenish color.
Properties
Granite is a rock that is distinguished by enviable strength, which is why it has been used in the construction industry since ancient times. The stone serves for a very long time, is resistant to rain and winds, and is able to withstand any climatic conditions. Few people know that the pyramids in Egypt are partially made of granite blocks. It was from this stone that many buildings in India and ancient Rome were built. It is processed and polished quite easily, and the degree can be brought to the point that the surface of the plate even becomes a mirror.
Compared with marble, this material twice as strong due to the fact that granite contains quartz. During the use of diamond drills. It is known that, despite its beauty and splendor, marble is very sensitive to temperature changes, which cannot be said about granite: it perfectly maintains its performance in the most severe conditions . Due to its strong structure, the stone much less susceptible to fungal attack than other materials .
The level of moisture absorption in the rock is low: the fine-grained structure of granite plays a key role in this. If it is denser - it is a breed with the best properties. They depend on the origin of the granite. The origin of the stone, in turn, determines the depth of its occurrence, it affects its density and strength.
The fact that granite is one of the most durable materials, and its performance is always at the right height, is largely ensured by the fact that it hardly absorbs moisture . This was the main reason for the use of stone for the design of embankments. By the way, the vast majority of the granite banks of the Neva were built under Peter I, which once again confirms the durability of granite.
Geochemical classification of White and Chappell granitoids
For the convenience of designating one or another type of granite stone, in the mid-70s of the last century, a brief analysis of granitoids was made based on their most common types.
In this analysis, four types of stone were distinguished - S, I, M, A:
- Sedimentary (S)- the stone is the result of the melting of rocks of the metasedimentary type;
- Igneous (I)- product of melting of substrates from metamagma;
- Mantle (M)- a stone formed from magmas, which include tholeiite and basalt rocks.
The chemical composition of granite S is similar in most elements to granitoids I, with the difference that stones S contain little calcium and sodium. Later classification appeared type A granite , which differs in composition from subalkaline type stones and consists of a large number of incoherent chemical elements.
Classification of granitoids by grain structure
The size and structure of the grains of different types of stone is different from each other.
Based on this, granite is of the following types:
- if the grain size does not exceed 2 mm - fine-grained;
- grain size up to 5 mm - medium-grained ;
- coarse-grained view - more than 5 mm.
The stone of the fine-grained variety will have the highest level of resistance to mechanical damage. It is characterized by more uniform abrasion over time, resistance to winds and high temperatures. The fine-grained fraction is always the most expensive. It practically does not absorb water and at the same time is highly resistant to fires.
When building houses, a coarse-grained type of granite is often used. It is cheaper, so after fires, you can often see granite stairs that have cracked and are no longer usable.
The names of granite, based on the mineral composition
Depending on what is the main mineral composition of granite, different types of stones are called differently:
- not containing dark colored minerals - alasquite;
- with a low content of dark flowers - leucogranite;
- biotite- if this mineral in the composition of granite is from 6 to 8%;
- if the stone contains biotite and muscovite at the same time - two-mica granite ;
- if the stone contains micas from lithium - this is lithium fluoride granite ;
- with a high content of alkaline components - simply alkaline granite ;
- a rare species consisting of orthoclase, quartz rocks and augite - pyroxene.
Varieties of granite based on its structure
The grain structure of the stone also varies.
Below are the main types of granite, named based on the structure of its grains:
- porphyritic- it is characterized by brightly standing out longish inserts. They differ from the main body of the stone in that they protrude from it. These are quartz, orthoclase, microcline.
- Granite pegmatoid - differs in symmetrical and uniform level of granularity.
- Rapakivi- Finnish type of stone with rounded inserts (red with a gray or gray-green frame).
- gneissic- the most common stone, having a fine-grained structure.
Of course, for a person who first encounters the fact that there are a lot of varieties of granite, it can be difficult to figure out which one is the best. It all depends on the purpose for which it is planned to use this material. There are a lot of options for use, and the quality and reliability of granite is much higher than that of the more popular marble.
It is known that marble quickly darkens and deteriorates under the influence of temperature changes and high humidity, and granite will stand for a very long time without changing either the structure or the original color of the stone. In addition, for lovers of white stone, there are special types of granite, which, when properly processed, are indistinguishable from marble at first glance.
Thanks to the excellent performance characteristics of granite, which has proven itself for many centuries, it is always possible to use it as a reliable building material, as well as for making decorative elements. Since any product made from this stone is unpretentious in use, this stone does not require special care. It will stand up to any bad weather and will serve for centuries.
The only disadvantage of granite is that among building materials it has the greatest weight, which must certainly be taken into account when designing bridges, monolithic houses and other large structures.
Granite is the most common rock in the crust of our planet. The word "granum" in Latin means "grain", which seems a little strange and unexpected to non-specialists. After all, we are all accustomed to considering it a homogeneous monolith, characterized by great strength. What grains is this stone made of? What is granite made of and what does it look like?
Total information
According to geologists, granites can be called the visiting card of the Earth, since the role of these stones in the structure of the earth's continents is significant. Whether there is granite on other planets orbiting the Sun is not known to astrophysicists for certain, although there is indirect evidence of the presence of stone on Venus. In addition, scientists suggest that our planet is made of the same substances as other terrestrial planets.
As for the origin of the granites themselves, this mystery still remains unsolved. Scientists suggest that the stone was formed as a result of the immersion of the solid substance of the earth's crust into the upper mantle and its melting there. Perhaps modern technologies and instruments will help scientists find answers to their questions.
What minerals are granite made of? Granite is a rock composed of 60-65% feldspar, 25-35% quartz, 5-10% mica - biotite/muscovite. The colors and strength of granites depend on the ratio of these main components.
Types of granite
In the earth's crust and on its surface, you can find different types of granites, and they all differ in mineral composition, structure, grain size. A stone with a high content of quartz and a low content of mica is considered to be of higher quality. If the stone contains pyrite, it will cause rusty and brown spots, and rapid destruction.
Ideally, if the quartz grains in the rock are in close contact, and other minerals in a fine state, fill the gaps between them. If quartz granules are surrounded by other minerals, the quality and strength of granite is reduced.
According to the mineral composition, granites are of the following types:
- There is a lot of plagioclase in plagiogranite, and a small amount of feldspar, which gives the stone a red or pink color. There are plagiogranites that do not contain feldspar at all.
- In pink alaskite, there is a lot of feldspar, and a very small amount of biotite. Dark-colored inclusions in feldspar are absent or present in small quantities.
Types of granites by structure and texture:
- Granite porphyritic - contains elongated inclusions of different lengths. Basically, it is quartz, microcline or orthoclase, 10-15 cm long.
- Porphyritic granites, consisting of rounded pink feldspar grains surrounded by light gray plagioclase, are called rapakivi granite. Granite of this type is not very durable, and quickly crumbles under the influence of external factors.
By the size of grains-granules:
- Grains-granules of stones can have different sizes from one and a half millimeters - up to 1 centimeter. A stone with granules larger than 1 cm is called coarse-grained; stone with granules from 2 to 10 mm - medium-grained; granules less than 2 mm are characteristic of granite with small grains.
Physical properties
Description of the properties of stone: fine-grained granite, in fact, is eternal. Medium-grained and coarse-grained and types are less durable, but they will be enough for more than one generation of users.
Granite is resistant to rain, snow, wind and acids. Differs in high durability to compression and friction. Its compressive strength is twice that of marble.
Granite does not absorb water, the high water resistance of the stone makes it possible to use it for facing fountains, pools, embankments. The beauty of the texture of granite and the variety of colors allows it to be used unpolished or polished to a mirror finish without additional coloring. In any case, it looks decorative due to inclusions of mica, creating a fascinating play of light, and various colors - blue, gray, pink, red, orange, green.
Granite is also widely used due to its good compatibility with other finishing and building materials - metals, clay, wood, ceramics, artificial stones, marble.
The description of granite would be incomplete without mentioning that the stone is environmentally friendly, it does not contain impurities that are harmful to health, it does not emit radio waves. That is, the stone is completely safe and can be used in the construction and decoration of premises for various purposes.
Mining
Granite is mined on all continents of the planet, there is no shortage of this stone. Only in Russia there are about 50 stone deposits located in various regions of the country.
Also, granite is mined in Ukraine. Granite deposits stretch in a wide strip from the southeast to the northwest. The length of the strip is 1000 km, the width is 200 km, in some areas the strip comes to the surface.
In the USA, granites are mined in the eastern part, on the coast of the Atlantic Ocean.
Where to apply?
“Fresh”, or recently mined granite from unweathered massifs has the best consumer characteristics, therefore, it is used in construction, as well as for the production of other products.
Fine-grained or medium-grained species have a denser structure, they have fewer pores, so they are stronger and more resistant to weathering.
Coarse-grained granite is used less often in construction, and only if the feldspar in them is absolutely fresh, without cracks, turbidity, and white powder formations.
Granite slab, consisting of a large amount of quartz, is used in places with high traffic. Floors and stairs are made of durable granite, it is especially necessary in public places, where many people pass during the day.
Countertops, cornices, window sills, bar counters, columns are made from granite - they can be installed both inside the building and outside.
Granite is used to make decorative tiles, monuments, commemorative plaques, memorials and obelisks.
The stone is suitable for arranging Japanese stone gardens, rockeries, alpine slides, for lining ponds, and laying paths.
In road construction, granite is used as curbs and paving stones.
Metaphysical properties
Granite, as an integral part of the earth's crust, also has metaphysical properties. It activates the activity of the brain, develops and strengthens memory, enhances intuitive abilities, helps to find a non-standard solution to a particular problem.
The healing properties of the stone are manifested in the treatment of diseases of the heart, lungs, bronchi, throat.
Granite has a beneficial effect on the body during colds, lowers the temperature, increases vitality. A strong and durable mineral strengthens the human musculoskeletal system - joints, spine, bone tissue.
Granite will become a good talisman for people whose professions are associated with risk - pilots, astronauts, geologists, sailors, rescuers, security officials. Granite will help teachers and lecturers, since their professions are considered the most difficult and even harmful to health today. They need granite to find new approaches in the educational process, strengthen the nervous system, increase resistance to stress.
For students, graduate students, students and schoolchildren of different ages, granite is useful for the development of memory and mental abilities.
The use of granite since ancient times had not only an aesthetic value, but also a functional side. Today, the stone is polished, ground, the surface of the processed samples has many names - polished, sawn, bush-hammered. For certain purposes, the stone is treated with fire. And all this variety of granite materials serves the conscience of a person.
The most durable, practical countertops and window sills are obtained from stone, which are also quite original due to the texture and color of the mineral. There are even fashion trends associated with cladding with this material. If earlier smooth surfaces were popular, today textured elements are in use. They conditioned the use of granite as a floor covering to avoid shoes slipping. Walls with textured design are also in fashion, it gives the interior a rich look and sets the main tone for the style decision.
It is clear that properties and areas of application of granite are interconnected. So, the hygiene of the stone, moisture resistance make it possible to create sinks and bathtubs from it. In addition, the mineral has high heat resistance, which is only a plus for the material used for such premises. The stone gives a person comfort and aesthetics in everyday life.
And yet the main thing for which he has been loved for centuries is his presentability. Majestic staircases, magnificent sculpture, harmonious borders and paving stones, monumental structures made of granite have been and will continue to be created as long as the mineral is formed in nature, as long as the reserves of this unique “eternal” stone allow.
