You will be surprised to know that granite masses make up the majority of all solid matter on planet Earth. But being the base of the earth's crust, they are almost completely hidden from our eyes. Only granite rocks and open deposits of this valuable rock give us the pleasure of using durable, beautiful material in construction and decoration. The composition of granite itself and the physical and chemical processes of its crystallization are also interesting and surprising.
Many elements took part in the formation of granite rock: high pressure, temperatures of thousands of degrees and gradual cooling over thousands of years in the depths of the earth's crust. It is thanks to the unique crystallization process that we have the pleasure of admiring the unsurpassed beauty of this natural stone.
What is the chemical composition of granite?
In the formation of the granite massif, the strongest rock after diamond, corundum and topaz, many chemical elements are involved, among which the main ones that determine the composition of granite are:
- Iron
- Potassium
- Manganese
- Aluminum
- Silicon
- Sodium
- Calcium
- Oxygen
- Hydrogen
Lithium, chromium, titanium, and tungsten are also found in small quantities.
As part of complex chemical compounds, the listed elements form minerals, which, in the form of compacted small grains, form the granite we are familiar with.
Mineral composition of granite
Minerals are usually called homogeneous natural compounds (in simple terms, stones) that have only one substance in their chemical composition.
In the composition of granite we find:
Biotite is the least of it, from 5 to 10% of the total mass. Biotites are the main decoration of granite rock: these are the shiny micas familiar to everyone. Their inclusions give the look magical shimmers when the viewing angle changes. The formula of biotite is very complex; it contains potassium, manganese, iron, aluminum, hydrogen and oxygen.
In small quantities, granite also contains muscovite (this is also mica) - a stone of various shades, from milky yellow to silver and green.
Quartz - those who remember chemistry lessons well will immediately say: this is “natural glass”, or silicon oxide. Quartz makes up approximately 25-35% of the substance of granite rock.
Feldspars are a collective group that includes acidic plagioclases and predominantly potassium feldspars. The percentage of this group of stones is the largest and ranges from 60 to 65%. It is not for nothing that minerals of this group were included in the composition of granite: it is the most common stone, accounting for approximately 50% of the total mass of the earth’s crust.
Plagioclase is a rather interesting mineral in its composition. In its pure form, it is a stone with sharp oblique cleavage planes, which is why the Greeks called it “oblique stone.” Its formula is also very interesting: Ca. It turns out that most of it is just oxidized metals and silicon.
The group of potassium feldspars are four minerals that have the same formula KAlSi 3 O 8, but due to different crystallization conditions, they received different ordering of the crystal lattice.
What is included in the composition of granite can be roughly determined by its color and texture: after all, at each deposit there is an absolutely unique rock with its own unique mineral structure and chemical composition.
How does the composition of granite affect its decorative properties?
There are a huge variety of granite grades, and each stone has a unique color, structure, grain size and texture.
Geologists conventionally divide granite rocks into groups:
- Plagiogranites - the mineral composition of granite is dominated by plagioclases, which are “responsible” for the light gray color of the stone. A small amount of feldspars can only slightly tint the stone a light pink shade.
- Alaskites - the predominantly mineral composition of granite is composed of potassium-sodium feldspars with small admixtures of biotites. Alaskan stones in their pure form are pink in color.
However, we know in practice that the color range of granite rocks is much wider. That's right, a wide variety of colors and shades are obtained thanks to minor admixtures of metal oxides, which color minerals in colors that are unusual for them.
Thanks to such “additives” in the mineral composition of granite, we can see rocks of all colors:
- Black - Absolut Black or Black Galaxy, Gabbro brands.
- - Imperial Red, Kapustinsky, Leznikovsky.
- Yellow - Sunset Gold, Crystal Yellow.
- Green - Green Ukraine, Maslavsky (Verde Oliva), Butterfly Green.
- Blue - Ultramarine, Sodalite Blue, Azul Macaubas.
- Colored - coarse-grained or fine-grained, with the most unexpected color combinations. For example, Didkovichsky, Yuzhno-Sultaevsky, Beinbook Brown.
The huge variety of natural stones found in deposits around the world is derived from the unique chemical composition of granite. Nature created crystallized masses according to special “recipes” and for each brand the mineral composition of granite is completely unique.
What else is included in granite?
An alternative classification of granites based on the principle of whether granite is composed of magma or sedimentary rocks is widely used abroad and comes down to the identification of 4 groups:
- S - it is believed that granitic rocks of this group are composed of melting products of metasedimentary substrates.
- I - this group consists of melted metamagmatic substrates.
- M - crystallized tholeiitic-basaltic magmas.
- A - melted lower crustal granulites are added to the differentiated magma of the alkaline-balsatoid composition.
Scientists are still engaged in heated debate over the origin of this truly amazing stone, which, by the way, is found only on Earth. The physicochemical processes of crystallization, as well as the true origin of the crystallized masses, have not yet been thoroughly studied.
But whether it is modified sedimentary rocks or frozen igneous masses, granites amaze with their unique beauty and high strength, due to which they are widely used in decorative finishing.
The great mystery: why do the minerals in granite have exactly this ratio?
Another amazing fact that baffles almost all geologists and chemists can amaze anyone. After all, if you follow the generally accepted theory of melting of solid crustal matter, when low-potassium granite material is formed, which makes up only 20% of the total mass, 80% of the solid residue should remain, in which there is no water. These must be minerals: pyroxene, the same plagioclase or garnet. But during research such layers were not found!
What lies hidden in the depths of the earth’s crust with huge layers of granite rock can only be guessed at. One thing is undeniable: the composition of granite is truly unique, although scientists have not yet been able to find similar rocks on other planets.
Granite is a universal natural material that has been used in construction since ancient times. Its strength, resistance to sudden temperature changes, dirt and moisture penetration. Increased hardness, durability and density allow it to be used in the construction and finishing of all types of houses, both residential, offices, shops and others. And the natural beauty of granite allows the building in which it is used to become individual and unusually beautiful.
Types of granite
Granite is formed after igneous rocks harden during a lava eruption. When combining it with other natural rocks (roseblende, quartz, feldspar, mica). This stone acquires amazing, and most importantly, natural colors and patterns, depending on the predominance of any rock. Granite may have inclusions, stains, it can be matte or shiny.
Granite of different colors is mined in different deposits. And every country rich in granite deposits is famous for its types of granite. Grey, blue-gray, white, red, red-brown, pink, orange, green, black, everything, their shades can be mixed and produce an extraordinary effect of iridescent shades.
Advantages of granite
- Granite is a very durable material and is quite difficult to break and almost impossible to damage, for example, scratch or chip.
- It is not exposed to fungi, mold, chemicals, or water.
- It has quite a lot of weight and granite tiles are now being made for decoration, which can be used both outside and inside the house. These tiles are particularly durable and will last much longer than tiles made from other materials.
- Granite goes well with other materials and can be combined with concrete, plaster, wood, ceramics, or even plastic.
Where is granite used?
The decoration of walls, floors, and ceilings is used in various styles and is relevant in any interior. The production of granite steps and balusters, window sills, countertops, cornices, fireplaces, columns, baseboards, flowerpots, statues is only a small part where granite is used indoors.
Outside the premises, granite is used both for construction and for cladding buildings. It is used to finish the base, this protects it from moisture and other destructive factors. Decorating walls, making stairs, pediments, pillars, balconies, benches, fountains, all this can be made from this stone.
Foundations are built from granite, which are particularly durable. And walls are built that perfectly keep things cool in the hot summer and keep the cold out in the cold winter. Special buildings with a high radioactive background are built from this material, for example, storage facilities or boxes, since this material copes well with radiation and any chemicals and does not release it outside.
For the construction of walls, granitoids are often used, that is, granite with the addition of other natural materials. Such a house is particularly durable and has a strict, unique beauty. This house can stand for many years and its beauty will not fade, since granite is not destroyed by wind and precipitation, and it is easy to clean with plain water or using detergents that cannot harm the granite surface. This type of building material is popular in many countries, since houses and foundations on this basis always guarantee the reliability of such a structure. Granite has always been and will be valued, since this material is made by nature itself and it adds sophistication to any type of room.
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 severe 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.
If you ask the first person you come across which rock is, in his opinion, the most durable, he will most likely say that it is granite. The stone made from this mineral is very hard and practical, as well as quite attractive in appearance, and therefore it is very often used in construction. In addition, it is often used to create various decorative elements, including monuments. The name of this breed comes from the Latin word “granum”, which means “grain”.
What is granite made of?
The main components of this widely distributed mineral in the earth's surface are feldspar and quartz. What does granite stone look like? Photos and descriptions of various types of this rock indicate that this stone can differ significantly in color, be completely different from other varieties and take on various shades, ranging from pale pink to gray. The color of granite mainly depends on the mineral, which in its mass fraction predominates over the other components that make up the rock. usually represented by various types of potassium spar and may be supplemented with albite or oligoclase. And quartz inclusions in granite look like small glassy grains. The latter can be either slightly bluish or colorless. In addition, when answering the question of what granite is made of, you should definitely note inclusions of muscovite and biotite, as well as elements such as zircon, magnetite, titanite, apatite and allanite. However, their content in this mineral is very, very insignificant. Listing everything that granite consists of, we note that with the predominance or shortage of certain components, it begins to be classified as other types of rocks. So, if it has too little potassium feldspar and quartz, then it falls into the group of diorites or quartz monzonites. And if there is too much plagioclase in granite, then this mineral will be considered granodiorite, and if the content of dark-colored minerals is too low, it will be considered leucogranite.
Deposits and production
After we have examined in detail what granite is made of, we will tell you a little about where this mineral is found and where it is mined. In nature, this rock occurs in fairly massive strata known as batholiths. Their thickness is 3-4 km, and their area often exceeds 100 square kilometers. Granite deposits can also take the form of stocks and dikes. Often the layers of this mineral are located one above the other, and sedimentary or metamorphic rocks act as interlayers. Deposits of granite rocks exist on absolutely every continent.
Most often they are found in places where strong erosion and denudation processes took place, due to which the integrity of sedimentary rocks was damaged. In the United States, granite deposits are located near the Ozark Plateau, in the foothills of the Rocky Mountains and in the Black Hills. In Russia, this mineral is mainly found in the Urals, in the eastern part of Siberia and in the Far East.
Rocks have been formed within the Earth for millions of years during geological processes. Granite occupies a special place among them.
Since ancient times, people have studied the properties of this stone, which is why it is so widely used in various fields of construction. Granite has gained popularity due to its beautiful grain structure, strength, durability, resistance to any weather conditions, fire, fungi, aggressive environments, and water resistance.
Natural beauty of stone
New technologies have made it possible to use granite more often, since it can now not only be easily processed, but also improve its decorative properties.
Granite is offered for sale in the form of blocks, chips or crushed stone. The last two are used to make various products.
This stone is very beautiful in its raw form, and after polishing it demonstrates its aesthetic merits even better, showing wonderful mica inclusions.
If the rock is chipped, the granite acquires a relief structure in which light and shadows play effectively. There are types of gray granite that become milky white as a result of heat treatment.
In general, there are many types of granite, so there is plenty to choose from to create a special cladding. The pattern is never repeated on the cut.
Granite is not a very cheap building material, so they came up with porcelain stoneware, obtained from clay and minerals as a result of firing. It is almost as good in properties as natural stone, although, of course, it is in many ways inferior to it in beauty and strength.
Granite has been used for construction and facing work from time immemorial to the present day due to its ease of processing:
- for cladding buildings and embankments in cold climates;
- make monuments and landmarks;
- they make steps, cover pavements, floors in entrances and public buildings;
- make columns, plinths, railings, tiles;
- used in the construction of swimming pools, fountains, bathrooms.
Granite is also widely used for interior decoration, as it goes well with ceramics, wood, metal and even glass. It perfectly decorates the design of the home.
This stone is used to make excellent countertops, sinks, and window sills. These products are easy to care for; they are not afraid of high temperatures and high humidity.
Granite is also used in landscape design in the form of gazebos, paths, borders that do not crack over time and are not afraid of any weather. The granite terrace and Japanese rock garden look nice.
Granite - review of native red and pink granite and measurement of its radioactivity:
