Granite description and characteristics for schoolchildren. What type of granite is it in origin? Appearance and physical properties of the stone

Granite is the most common rock in the crust of our planet. The word “granum” means “grain” in Latin, 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 granules is this stone made from? What is granite made of and what does it look like?

Total information

According to geologists, granites can be called the calling card of the Earth, since the role of these stones in the structure of the earth's continents is significant. Astrophysicists do not know for certain whether there is granite on other planets orbiting the Sun, although there is indirect evidence of the presence of stone on Venus. In addition, scientists suggest that our planet is created from the same substances as other terrestrial planets.

As for the origin of the granites themselves, this mystery also remains unsolved. Scientists suggest that the stone was formed as a result of solid matter from the earth's crust sinking into the upper mantle and melting there. Perhaps modern technologies and instruments will help scientists find answers to their questions.

What minerals does granite consist of? Granite is a rock consisting 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 earth's crust and on its surface you can find different types granites, and they all differ in mineral composition, structure, and 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.

It is ideal 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 decreases.

According to the mineral composition, granites are of the following types:

Plagiogranite contains a lot of plagioclase and a small amount of feldspar, which gives the stone its red or pink color. There are plagiogranites that do not contain feldspar at all.
Pink alaskite contains 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:

Porphyritic granite – 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 grain size:

Stone grains can have different sizes from one and a half millimeters 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 the stone: fine-grained granite is essentially eternal. Medium-grained and coarse-grained types are less durable, but they will last for more than one generation of users.

Granite is resistant to rain, snow, wind and acids. It has high strength 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 cladding fountains, swimming pools, and embankments. The beauty of granite texture and variety of colors allows it to be used unpolished or polished to a mirror finish without additional painting. In any version, 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.

A description of granite would not be complete without mentioning that the stone is environmentally friendly, it does not contain impurities harmful to health, and 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.

Production

Granite is mined on all continents of the planet; there is no shortage of this stone. In Russia alone there are about 50 stone deposits located in various regions of the country.

Granite is also mined in Ukraine. Granite deposits stretch in a wide strip from southeast to northwest. The length of the strip is 1000 km, 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 Atlantic coast.

Where to apply?

“Fresh” or recently mined granite from non-weathered massifs has the best consumer characteristics, which is why it is used in construction, as well as for the production of other products.

Fine-grained or medium-grained types have a denser structure, they have fewer pores, so they are stronger and more resistant to weathering.

Coarse-grained granite is used less frequently in construction, and only if the feldspar in them is absolutely fresh, without cracks, clouding, or formation of white powder.

Granite slabs, consisting of a large amount of quartz, are used in areas with high traffic. Durable granite is used to make floors and stairs; it is especially necessary in public spaces where many people pass through during the day.

Granite is used to make countertops, cornices, window sills, bar counters, columns - they can be installed both inside and outside the building.

Granite is used to make finishing tiles, monuments, memorial plaques, memorials and obelisks.

The stone is suitable for constructing Japanese stone gardens, rock gardens, alpine slides, for lining ponds, and laying paths.

In road construction, granite is used as curbs and paving stones.

Metaphysical properties

Granite, as a component of the earth's crust, also has metaphysical properties. It activates the activity of the brain, develops and strengthens memory, enhances intuitive abilities, and 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, and throat.

Granite has a beneficial effect on the body during colds, reduces temperature, and increases vitality. A strong and durable mineral strengthens the human musculoskeletal system - joints, spine, bone tissue.

Granite will be a good talisman for people whose professions involve risk - pilots, astronauts, geologists, sailors, rescuers, security officials. Granite will help teachers and lecturers, since their professions today are considered the most difficult and even harmful to health. They need granite to find new approaches in the educational process, strengthen nervous system, increasing resistance to stress.

Granite is useful for students, graduate students, students and schoolchildren of all ages for the development of memory and mental abilities.

Granite is considered one of the most durable and durable materials. That is why it has been so widely used since ancient times for the construction of structures, finishing facades and creating monuments. You can buy a monument in Minsk from this eternal natural material that can withstand more than one century by following the link.

Introducing Interesting Facts about granite.

1. Granite contains, in percentage terms, almost half of what we consume from the atmosphere - oxygen.

2. The hardness of granite retains its original properties for several centuries. Neither frost, nor heat, nor blizzard, nor rainfall - such a stone is not afraid of anything.

3. Granite is also a sound transmitter. So, the passage through it is 10 times faster than the passage through air.

4. When it comes to granite, many people imagine a less than happy picture in black and gray tones.

However, today, this stone can please you with other, brighter and more contrasting colors: red, yellow, orange, green. It turns out that the color is determined by the presence or absence of spar in it.

5. Fine-grained granite is considered the strongest and most resistant to all external destructive factors. That is why its average life span reaches 500 years.

6. Today, countries such as India, China and Italy are the main exporters of granite in the world.

7. And in Russia, by the way, there is its own “property” - a large building created exclusively from unpolished marble.

And it is located in the Irkutsk region and is a railway station.

8. There is also an unusual mountain, completely covered with granite and competing with Everest - Kanchenjunga, almost 9 km high.

9. Porcelain tile is an “artificial” version of natural stone. It appeared relatively recently and was able to greatly facilitate the work of designers thanks to the different colors and textures of the material.

10. According to some reports, there is an opinion that small granite accumulations became “pioneers” in the creation and appearance of life on Earth. To what extent this is reality or a myth is unknown, but some scientists are inclined to this opinion.

Other interesting facts about granite can be found on the Internet.

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 forms the outer part of the earth's crust.

The name “granite” comes from the word “granum”, which means “grain”. We are, however, not talking about wheat or rye grains, as you yourself understand. Grains are crystals of quartz, mica, feldspar, hornblende and other minerals that are components granite. The color of granite 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 Earth's surface, like a huge blanket, prevent the magma from cooling too quickly. Granite is exposed only when the outer coverings are “weathered,” that is, destroyed by water, wind, ice, or as a result of movements in the earth’s crust when granite blocks are pushed to the surface.

After this, however, the granite itself undergoes weathering. The first to break down are the feldspar crystals, which turn into a mixture of clay and salts. Only quartz is able to withstand 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. It is used for the construction of facades of large buildings, monuments, as well as for the production of gravestones and tombstones. The ancient Egyptians used it to build temples and the famous pyramids.

Mineralogical composition of granite.

Granite includes a wide range of minerals. Acid plagioclase is rock-forming minerals, aluminosilicates from the feldspar group. Plagioclases are a series of extreme member minerals, which are albite Na(AlSi3O8) abbreviated Ab and anorthite Ca (Al2Si2O8) (abbreviated An). Typically, the composition of the rock is designated by a number corresponding to the anorthite content as a percentage. Albit No. 0 - 10; oligoclase No. 10 - 30; andesine No. 30 - 50; Labrador No. 50 - 70; bitovnit No. 70 -90; anorthitis No. 90 - 100.

Primary colors of granite. What determines the color of granite?

Minerals that make up rocks can have different colors. This is explained by the mineral composition of which the rock is made. So if Si, Al, K, Na are present in the rock, then they will be colored in light colors (quartz, muscovite, feldspars). And if Fe and MgCa are present in the rock, then they will have a dark color (magnetite, biotite, amphiboles, pyroxenes, olivines).

Color range of minerals

What rocks form granite?

Granite is a material that was formed from igneous rocks. Igneous rocks are formed when cooling magma hardens both underground (intrusive) and on its surface (effusive). According to the alkali content, igneous rocks are divided into rocks of the normal series (that is, the ratio of the sum of alkalis to the alumina content<1) , щелочного ряда (отношение >1). According to the silica content, SiO2 can be acidic (silica from 67 to 75%), moderately acidic (from 67 to 52%), basic (from 40 to 52%) and ultrabasic (<40%)

What is granite made of?

Granite is a material that is used in the construction industry. But in order to use it, it must be processed and given certain sizes and shapes. After processing, this product is called crushed stone. can have different sizes, starting from 1 mm and ending with 120 mm (rubble stone). Crushed stone can also be classified according to shape, that is, according to the content of cuboid-shaped grains. The cuboid shape of crushed stone directly characterizes the level of adhesion to the binder components in the solution. The higher the cubicity index, the lower the consumption of crushed stone and other materials, since it is more compact, which means there will be slight shrinkage, and therefore the structure will have increased rigidity. One of the types of products obtained is granite screenings or

Granite stone is not just the most common rock on Earth. Granite stone, the properties of which have long become a model for the formation of a male character, personifies power, inflexibility, strength, and timelessness.

Minerologists, of course, are well aware that granite is not an eternal mineral, and it was the granites destroyed by weathering that formed the basis for the formation of soils. Nevertheless, in the general human perception, this stone symbolizes pathos, greatness, and reliability.

Granite boulders of national parks, granite walls of thousand-year-old castles, granite paving stones of ancient pavements. And also granite monuments of history and culture; steles and statues carved from beautiful stone, huge monoliths and small colored chips... Granite is the most useful mineral!

Granite - from the word granum (“grain”)

All granite is grainy. Its origin is associated with volcanic processes. Magmatic melts, which absorb small fragments of previously destroyed rocks, turn into granites when cooling. Metamorphic processes leading to sintering and partial melting of fragments also lead to the appearance of granite.

It is often impossible to understand what kind of genesis is inherent in a particular granite massif, but regardless of origin, the physical properties of granite are the same.

Strength is an important distinguishing feature of a mineral. The stone can withstand pressure of more than 600 kilograms of load per 1 cm2 of surface. Granite is also characterized by high density. A centimeter cube of stone is three times heavier than the same volume of water.

The hardness of granite (up to 7 Mohs points) is ensured by the presence of quartz in the mineral composition. It is quartz that helps the stone withstand huge (more than 100˚) temperature changes. However, the thermal resistance of granite due to the same quartz is reduced: the stone melts when heated to only 700˚C - which did not allow granite structures of antiquity to withstand strong fires.

However, the performance characteristics of granite are considered high enough for the construction of the most pretentious buildings. It has been experimentally established that fine-grained granite exhibits the best properties. If the stone grain does not exceed two millimeters in diameter, architects and builders can easily find a use for this excellent natural material!

Applications of granite

The heaviness of granite products limits the use of stone in mass modern construction. However, in individually designed residential and public buildings, granite steps and window sills, interior and architectural elements, paving and cladding can be used.

Our distant ancestors were also partial to beautiful and durable stone. Granite buildings in Machu Picchu, creations of ancient Egyptian architecture, massive structures of ancient Europeans pose difficult questions for historians. It is still unclear how our ancestors managed to process a stone that can only be processed with a diamond tool?

In modern conditions, granite has become a mass construction material, but not in the form of slabs and blocks, but as a concrete filler, ballast material for railway embankments, and crushed stone underlying the asphalt layer.

Pavements made of granite blocks are also irreplaceable. Only streets paved with natural stone remain on the steep mountain slopes. Asphalt flows under such conditions.

The desire to imitate everything and everyone led humanity to the creation of porcelain stoneware. Mineral components mixed with the polymer mass have nothing in common with natural granite. However, some external similarity is observed...

Granite can be beautiful

More precisely, granite is never ugly. Even the most ordinary gray granite is an excellent material, in demand by both architects and sculptors. Inclusions of various minerals give shades to the gray stone.

Hornblende causes the mineral to darken, turning brownish-green. Amazonite granite is famous for its light green hue. Black quartz granite is solemn and strict. The amethyst granites of Sweden reflect purple and pink.

Mining of colored granite is carried out everywhere. The rarest blue granites are exported from the north of Europe. Red porphyry granite, mined in areas of volcanic activity that died out millions of years ago, is sold in the most expensive and pompous construction projects. Black granite is a favorite material of sculpture workshops around the world.

From ancient times to the present day, marble and granite have symbolized the power and wealth of those in power. The symbolism of the stone does not lose its meaning and does not change its content for dozens of centuries! However, many legends concerning granite have been born in our time.

Myths about granite

It is generally accepted that granite is expensive. In fact, man-made mineral-polymer stone has a higher retail price than common varieties of granite. Although rare and beautifully colored varieties of natural stone - especially in large monoliths - can exceed the cost of any building materials.

There is an opinion that graininess, cracking and porosity are defects of granite. And that the user of a granite product is doomed to spend the rest of his life on constant and continuous care for the polished stone. In reality, even the most moisture-intensive types of granite can handle treatment with hydrophobic resins once every ten to twenty years.

The tendency of granite to crack under the influence of high temperatures is also exaggerated. If granite were thermally unstable, its weathering would take place over several years. In fact, the natural destruction of stone sometimes lasts for many millennia. In landscape photos, the granite of rocks, boulders and cliffs often appears to us in its original form. So at home, a hot frying pan placed on a granite countertop will not do any harm.

The level of radioactive radiation in granite is also considered dangerous. The natural background of the stone actually exceeds the radiation level in the clearing of the birch grove by approximately twice. However, this is exactly half the level allowed by sanitary standards.