Granite and its properties. Granite - characteristics and properties of the rock What does granite mean?

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 of 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.

Rock composition

What is this breed made of? The mineral composition of granite is based on minerals formed during the crystallization of magma, such as plagioclase, potassium feldspar, quartz, and mica. Granite derives its composition from igneous plutonic rocks of high acidity.
The basis of the earth's crust, its most important rock, is granite stone. However, how such minerals are formed is still not completely clear. There is an assumption that during the crystallization process, basaltic magma is gradually saturated with various chemical elements. Moreover, this process is subject to a certain pattern. At the end of this complex and long path, differentiates are formed - derivatives of a certain basaltic melt. The chemical composition of granite indirectly indicates the veracity of this assumption. After all, the rock is saturated with fusible sodium, potassium, and silicon.

The basis of the earth's crust, its most important rock, is granite stone

Stone has many faces. Its structure may be different. It can be fine-, medium- and coarse-grained. The finer the grain fraction (from 2 mm), the stronger the rock, the less susceptible it is to various atmospheric phenomena.

Gallery: granite stone (25 photos)

Color variations

Varieties of granite find different applications in areas of human activity. In many ways, color is decisive. It can be red, black, gray, beige, brown, bluish and even pink. Quartz and mica fragments in the composition give the stone, illuminated by the sun or artificial light, a sparkling appearance.

Granite gets its colors from the feldspars it contains.

Pink granite is also called amethyst for its shades from delicate to deep purple. Its deposits on Russian territory are in Karelia. And in Brittany there is Pleneuf-Val-André, the coast of which is called the Coast of Pink Granite for the unique delicate color of the boulders.

Varieties of granite find different applications in areas of human activity

Rich red slabs can be found in the decoration of buildings, bridges and embankments.

If the composition of the rock is dominated by black quartz, then the color of the granite is black. This variation is in great demand when constructing monuments, along with marble. Solemnly austere and at the same time radiating brilliance, such a stone looks stunning both in the form of a stele and as part of a composite monument.
Green color is rare. Gray is the most common in construction.

Stone of the Amazons

Amazonite granite among others looks magical. Its greenish-emerald hue looks perfect in jewelry boxes, snuff boxes, ashtrays and even beads embodied in stone.

The first deposit of this rock was discovered in Mongolia. But earlier it was also found in Scythian burial mounds in the form of jewelry, household items and even weapons. Herodotus and Pliny also associated this interesting name of the stone with the militant Amazons (from the Greek “amazon” - breastless).

The works of ancient scientists contain a description of these women who, worshiping the goddess of fertility, sacrificed their breasts to her. One of the legends puts forward the version that the use of granite by the Amazons made it possible to do without the brutal amputation of the right breast. Instead, warriors rubbed it with green amazonite powder from childhood. This, of course, is just a beautiful version, but it is not without scientific background.

The breed comes in shades from green to almost blue. This is a beautiful finishing and ornamental material.

Traces of tantalum and tin are often found in its composition. It is found on the Kola Peninsula and the Urals. Other mining sites are Madagascar's Antananarivo and Zimbabwe.

Which is better, granite or artificial stone (video)

Artificial or natural

Despite widespread mining, the properties and uses of natural granite do not always satisfy the goals of the end user. And price is not always the deciding factor. Although she is not small.

Artificial granite successfully solves problems that are difficult for natural granite. Products made from it look amazing.

It’s difficult to call a stone unnatural: consisting of 80% natural granite chips, it is even outwardly indistinguishable from natural stone.

The characteristics of artificial granite differ little from the characteristics of natural stone. But the price differs noticeably.

The main advantage is the ability to form almost any shape specified by human imagination, because granite is formed from a viscous mass.

Its properties are somewhat inferior to the natural mineral. But a lot depends on the quality of the components and the integrity of the manufacturer.

It is sometimes difficult to distinguish between materials created by nature and man-made. There is only one characteristic of granite that will help you do this. Tap the surface with a metal object: if it is natural, the sound will be loud, and if not, it will be muffled.

How to determine quality

A brief description of a stone is usually not complete without mentioning possible cracks. But are they a marriage? Whatever the color of the minerals, the strength and durability of granite are determined by nature itself.

The ability to repel water and resistance to pollution, as well as numerous granite historical and architectural monuments with a history of several hundred years, allow us to assert that no minor natural defects in stones can affect their performance properties. The service life of granite products can reach up to 500 years.

The opinion about the radiation background of the rock, which can harm human health, is biased. The level of its radiation does not exceed the permissible level.
Granites are quite meltable. But hot kitchen utensils will never melt or damage a window sill or countertop made from this stone.

The stone is processed according to one or another scheme, depending on the purpose of the final product.
It is sawed, polished, ground, polished. Products are even made from cut granite.

Burching produces a grainy texture with an anti-slip effect. Imitation of natural chipping is widely used in the production of monuments.

Attention, TODAY only!

This is a stone of natural origin. It is mined in many places on our planet and there is a possibility that it is not found on other planets of the solar system. Therefore, granite is called “the calling card of the Earth” in different sources. This is one of the most durable breeds in the world. Granite contains 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. At its core, it is a rock. As already mentioned, it includes different minerals, and its composition is heterogeneous, in contrast to minerals (for example, quartz, amethyst, chrysolite), which are uniform in both structure and color.

The granite rock is ubiquitous in our lives: in the form of railway embankments, tombstones, wall cladding, street elements of decorated decorations. Granite products have long seemed to people the most common 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 it better: after all, few people think about what granite is made of and what the history of its origin is.

How did granite come about?

It is generally accepted that there are two natural ways by which this natural stone was formed. It could have arisen from molten magma (frozen volcanic lava). Deep in the earth's crust, magma slowly cools and turns into a fossilized structure, in which granite grains of different sizes crystallize over 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 another way. Sedimentary rock, as well as clay-like sand and various types of stones, were gradually displaced through 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 granite formation occurs in so-called collision areas. Two continental plates collide with each other, causing an increase in the layer of crust on the continent. Many scientists believe that it is as a result of the thickening of the collision layers of the crust that layers of granite melt appear - at a depth of 10 to 20 km. This phenomenon is called granite magmatism . It is most typical for Andean batholiths, as well as for island arcs.

Where are granite deposits located?

The main place where granite occurs is the batholith mountain ranges, the length of which is about 4 km and the area of several hectares. Sometimes during mining it is clear that several layers of stone have been formed: granite and its sedimentary rock. The stone itself appears in the form of wide layers, alternating with representatives of sedimentary and metamorphic species.

Like other minerals that are not very rare, granite has become widespread almost everywhere: it can be found on any continent . Due to the fact that over millions of years, ancient rocks gradually displaced younger formations to the top, 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 minerals and feldspar. Spar provides certain shades, and if the stone has a lot of translucent grain, it means 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 has little feldspar, it is called plagigranite. If, on the contrary, there is more feldspar in the stone and less dark flowers, this is Alaskan.

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%;
dark colored minerals granite - from 5 to 10% (mostly biotites).

Depending on which feldspars are included in the composition 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. The color also depends on what is included in the composition of granite from dark-colored minerals. If searchers come across a rock consisting of biotite or hornblende, the stone will be painted in dark tones. 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 its enviable strength, which is why it has been used in construction since ancient times. The stone lasts a very long time, is resistant to rain and wind, and can 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 structures were built in India and ancient Rome. It is processed and polished quite easily, and the degree can be increased to the point that the surface of the slab even becomes mirror-like.

Compared to marble, this material twice as strong due to the fact that granite contains quartz. During this time, diamond drills are used. 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 harshest conditions . Due to its durable structure, the stone susceptible to fungal attack much less 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, we are talking about 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, which affects its density and strength.

The fact that granite is one of the most durable materials, and its performance is always at the proper level, is largely ensured by the fact that it hardly absorbs moisture . This was the main reason for using stone to decorate 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 the 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 identified - S, I, M, A:

Sedimentary (S)- the stone is the result of the melting of metasedimentary rocks;
Igneous (I)- product of melting of substrates from metamagma;
Mantle (M)- a stone formed from magmas, which include tholeiitic and basaltic rocks.

The chemical composition of granite S is close to granitoids I in most elements, with the differences being that S stones contain little calcium and sodium. Later classification appeared type A type of granite , differing in composition from subalkaline stones and consisting of a large number of incoherent chemical elements.

Classification of granitoids by grain structure

The size and structure of grains differ from one another to different types of stone.

Based on this, granite comes in the following types:

if the grain size does not exceed 2 mm - fine-grained;
grain size up to 5 mm - medium grain ;
coarse-grained type - more than 5 mm.

A fine-grained stone 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 is highly resistant to fire.

When building houses, coarse-grained granite is often used. It is cheaper, so after fires you can often see granite stairs that have cracked and are no longer usable.

Names of granite based on mineral composition

Depending on what the main mineral composition of granite is, different types of stones are called differently:

does not contain dark-colored minerals - Alaskan;
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 - double mica granite ;
if the stone contains lithium mica - it is lithium fluoride granite ;
with a high content of alkaline components - simply alkaline type of granite ;
a rare species consisting of orthoclase, quartz rocks and augite - pyroxene.

Varieties of granite based on its structure

The structure of stone grains also varies.

Below are the main types of granite, named based on the structure of its grains:

Porphyritic- characterized by brightly eye-catching long inserts. They differ from the main mass of the stone in that they protrude from it. These are quartz, orthoclase, microcline.
Pegmatoid granite - characterized by a symmetrical and uniform level of grain.
Rapakivi- a Finnish type of stone with rounded inserts (red with a gray or gray-green frame).
Gneissic- the most common stone with 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 you plan to use this material. There are a lot of application options, 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 have proven themselves over many centuries, it is always possible to use it as a reliable building material, as well as for decorative elements. Since any product made from this stone is unpretentious to use, this stone does not require special care. It will withstand any 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.

Among the many rocks on Earth, the main group consists of igneous ones, which were formed over millions of years in the thickness of the earth’s crust from volcanic lava. These breeds include one of the main

building materials - granite. The properties of this stone have long been studied by people. This led to it being widely used in construction in the past, and it is still used today. A huge number of monuments and structures of antiquity have survived to this day due to the fact that they were made of granite. Its unique composition, beautiful granular structure and beneficial properties make this stone a very popular building material.

Granite deposits

This rock is formed as a result of the solidification of magma at great depths. It is affected by high temperature, pressure, gases and vapors rising from the thickness of the earth's crust. Under the influence of these factors, such a unique structure is obtained, the play of light and shadow that we observe in this stone. Most often it is gray in color, but sometimes red or green granite is mined. Its properties depend on the size of its constituent grains. It can be coarse-grained, medium-grained and fine-grained (the most

lasting).

This rock usually lies at great depths, but sometimes comes to the surface. Granite deposits are found on all continents and in almost all countries, but most of them are in Siberia, Karelia, Finland, India and Brazil. Its extraction is quite expensive, since it occurs in the form of huge layers, often extending for several kilometers.

The composition of this stone

Granite is a polymineral rock formed by several substances. Most of its composition is feldspar, which determines its color. Almost a quarter is occupied by quartz, which consists of inclusions of translucent bluish grains. Granite also contains other minerals (for example,

up to 10% it may contain tourmaline, up to 20% mica), as well as inclusions of iron, manganese, monazite or ilmenite.

Basic properties of granite

The advantages of this stone allow us even now to admire the architectural structures made from it in ancient times. What properties of granite determine its widespread use?

1. Durability. Fine-grained varieties of granite show the first signs of abrasion only after 500 years. Therefore, it is sometimes called the eternal stone.

2. Durability. Granite is considered the most durable substance after diamond. It is resistant to compression and friction. This is explained by the properties of quartz included in its composition. In addition, it becomes clear why this rock is so strong, after the answer to the question of what it is is found. It is actually very high - almost three tons per cubic meter.

3. Weather resistant. Granite can withstand temperatures from minus 60 to plus 50. This is very important in cold climates. Research has proven that granite products do not lose their properties after freezing and thawing 300 times.

4. Waterproof. It is thanks to this property that granite is so

frost-resistant. Therefore, it is ideal for cladding embankments.

5. Environmental cleanliness. Granite is not radioactive at all and is therefore safe for any construction work.

6. Fire resistance. This material begins to melt only at 700-800 degrees Celsius. Therefore, lining a house with it is not only beautiful, but also safe.

7. Ease of processing, compatibility with any building materials and a wealth of textures and colors make it indispensable for interior design.

8. Resistance to acids and fungi.

Granite processing

Despite the strength and high density of the rock, this stone is easy to process. It is quite easy to cut and polish. Typically, large granite blocks, slabs or granite chips and crushed stones are sold. It is used to make tiles, countertops and paving stones. The richness of textures of this natural stone makes the use of granite acceptable for decorating any interior. It looks very nice because it absorbs light well. Polished to a shine, it reveals all its virtues and the beauty of mica inclusions. When processing the rock using the chipping method, a relief structure is obtained with a decorative effect of play of chiaroscuro. And some types of gray granite become milky white after heat treatment.

Types of granites

Based on what minerals are included, it is especially worth paying attention to the dark-colored components. These are divided into several groups: alaskite, leucogranite, biotite, pyroxene, alkaline and others. These breeds also differ in structure:

Porphyritic granite, which contains elongated mineral inclusions;

Pegmatoid - characterized by uniform grain size of quartz and;

Gneissic is a uniform, fine-grained stone;

Finnish granite, which is also called rapakivi, has round inclusions of red color;

Written is a very interesting variety; in it, particles of feldspar are arranged in the form of wedge-shaped strips, similar to ancient writing.

Recently, artificial granite, created by firing clay with minerals, has also been used. This stone is called porcelain stoneware and is almost as good in properties as natural stone.

Types of breed by color

The properties and uses of granite also depend on its color. Based on this trait, several breed groups are distinguished:

Amazonite granite, due to the green feldspar it contains, has a pleasant bluish-green color;

Rose-red and red Leznikovsky are the most durable;

Gray rocks are very common, and they got their names from the places they were mined: Korninsky, Sofievsky, Zhezhelevsky;

White granite is rare. This variety includes colors ranging from pale green to pearl gray.

Applications of granite

This stone has been used in construction for many centuries and this is due to the fact that its fine-grained varieties begin to collapse only after 500 years. It is resistant to various impacts and very durable. These basic properties of granite allow it to be widely used in construction. Where is the mineral used:

1. Most of the monuments are made from it.

2. Its strength and abrasion resistance allow the stone to be used for making steps, flooring, porches and even pavements.

3. In cold climates, the most popular building material is granite. Its properties make it possible to cladding buildings and even embankments where

There are harsh winters.

4. This stone can transform your home both inside and out. Designers successfully use it to make columns, stairs, baseboards, countertops and railings. They also line the walls of houses.

5. The use of granite in swimming pools, bathrooms and fountains is due to the fact that it does not allow water to pass through at all. And also does not collapse under its influence.

Granite in the interior

In recent years, this stone has become very widely used for interior decoration. It goes well with all materials: wood, metal and ceramics - and is suitable for the design of any home. In addition to wall and floor cladding, granite can be used in many areas of the apartment. Its properties make this stone indispensable for making window sills and countertops in the kitchen. They are easy to care for, durable and do not deteriorate from exposure to moisture and high temperature.

Granite is also widely used in landscape design. A path or gazebo lined with this stone will not be afraid of atmospheric influences and will not crack over time. Flower beds decorated with it, for example, in the style or in the form of a terrace, look beautiful. It is also very convenient to use granite for making borders and stairs.

The properties and uses of this stone have been studied for a long time. And it has been used by man since ancient times. With the advent of new processing technologies, granite began to be used even more often, because it became possible to improve its decorative properties.

Granite, as a rule, has a granular structure: from fine to coarse-grained

Granite is a natural stone with a complex composition. Mainly formed from feldspars, mica and quartz

NAME

Granite (from Latin granum - grain)

COLOR

Depending on the proportional combination of minerals, it acquires different colors. It has a rich range of colors: from black to traditional red-burgundy and black to white and gray.

By the way, it is feldspar and quartz that create the “spotty” effect.

Granite can be coarse-grained, medium-grained and fine-grained. This amazing stone has a rich range of colors: from the traditional red-burgundy version with black speckles to white with gray splashes (and vice versa).

The most common granites are gray ("Sibirsky", 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 Atlantic coast (from Maine in the north to Georgia in the south), forming 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, there are about 50 deposits of granite suitable for use as piece stone, as well as rubble and crushed stone - on the Karelian Isthmus, in the Onega 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. The Ukrainian crystalline shield stretches across the entire territory of the country, from the northwest to the southeast. The width of its part directly exposed to the surface is 200 km, and its length is about 1000 km. It is on this strip that the main deposits of decorative stone are concentrated.

QUALITIES

1.Durability. The best grades of fine-grained granite begin to show the first signs of deterioration after more than 500 years, which is why it is often called an “eternal” stone;

2.Strength. Granite is highly resistant to friction, compression and abrasion. This 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 is 0.05–0.17%). That is why granite is perfect for cladding embankments.

5.Environmentally friendly. Contrary to prevailing prejudices, the natural radiation level of most granites corresponds to class 1 - i.e. they are radiation safe and suitable for all types of construction without restrictions;

6. Richness 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 capabilities of granite can satisfy even the most complex design plans;

7.Compatible 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 red, pink, orange, bluish-gray, and bluish-green are also found.

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 along 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, baseboards, railings, furniture table tops, coffee tables, bar counters, balusters, columns - the high strength of granite will allow these items to remain intact and unharmed for many years, and avoid mechanical damage from exposure to temperature and humidity;

Facade and interior finishing. Granite is a very ergonomic material that can provide you with a comfortable stay in the building;

Landscape design elements. Alpine hill, rock garden, Japanese gardens, decorative ponds - made of granite, these fashionable compositions will give your garden naturalness and originality.

Curbs, steps, paving stones. Granite is successfully used in places where greater “endurance” is required. It is resistant to mechanical stress, chemical contamination and temperature changes - it does not change its properties over hundreds of freezing and thawing cycles.

Facing embankments. 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 stones. The use of granite paving stones dates back thousands of years. The famous ancient Roman cobbled roads can still be walked today; you will find streets lined with paving stones 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

Since primitive times, man has become accustomed to trusting stone. This natural, living, “feeling” material will relieve psychological stress and bring coziness, tranquility and comfort to your home.

Have you ever wondered about the origin of the expression “gnawing at the granite of science”? Why, when talking about diligent and capable students, do we remember 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.