The healing properties of clay and its use in medicine. Types and properties of clay

Clay is a mineral that has found wide application in various fields life activity. This rather complex rock can be represented by different compositions and properties. Conditions of education different types clays also differ significantly.

What is clay?

Geological science has been studying rocks for quite some time. Scientists have found that clay, not contaminated with foreign impurities, consists of small particles. The diameter of the dust does not exceed 0.01 mm. These are particles that belong to a specific group of minerals. It is no coincidence that the use of clay has become widespread. The rock is a tangled chemical compound, which contains water, silicon and aluminum.

Clays change their properties under the influence of liquid. Depending on the amount of water that is added to the rock particles, a plastic mass or lime may be formed. Liquid with added clay has high degree viscosity This property is widely used in the construction and repair industries.

Properties of clays

The properties of any rock depend entirely on its composition. Clay is no exception. The size of the constituent particles also matters. When mixed with the rock, it is capable of forming a viscous dough. This property is widely used in various spheres of life. Clay swells in water. Thanks to this, it can be used very sparingly. In its raw form, clay dough can retain absolutely any shape. Nothing can be changed after it has hardened. And so that the product can be preserved for a long time, it is fired. When exposed to high temperatures, clay becomes even stronger and more durable.

If we describe the basic properties of clay, we cannot help but remember water resistance. Once the rock particles are saturated with the required amount of liquid, it no longer allows moisture to pass through. This property is also quite widely used in construction.

Certain types of clays are capable of purifying petroleum products. The same properties of clay are used to purify vegetable fats and oils. Thanks to this, people can consume foods without harmful contaminants. Clay absorbs liquids that can be harmful to health. For the same reason, certain types of rocks are used in cosmetology.

What types of clays are there?

exists in nature great amount types of clays All of them have found their application in one area or another of life. Kaolin is a light-colored clay that has less plasticity compared to other types. This is the breed most often used in paper industry, as well as in the manufacture of tableware.

Fireproof clay deserves special attention. This is a white or light gray substance that can withstand temperatures above 1500 degrees when fired. Under influence high temperature fire-clay does not soften and does not lose its beneficial properties. The rock is widely used in the manufacture of porcelain products, as well as in interior decoration. Facing tiles made of refractory clay are considered popular.

Molding clays can also be fired at a fairly high temperature. They are distinguished by increased plasticity. This refractory clay can be used in metallurgy. It is used to make special bonding molds for metal casting.

Cement clays are most often used in construction. These are grayish substances with an admixture of magnesium. Clay is used for the manufacture of various finishing products, and also as a connecting link during construction work.

How and where is clay mined?

Clay is a mineral that is not rare today. The substance can be extracted from the ground without any problems. It is easiest to detect the substance in places where rivers previously flowed. Clay is considered a product of sedimentary rock and the earth's crust. IN industrial scale Clay is extracted using excavators. The machine cuts away large layers of soil. In this way, much more minerals can be extracted. The problem is that the clay in most cases lies in layers.

Entire quarries serve as places for clay extraction. The work begins with removing the top layer of soil. Most often, clay can be found already at a distance of half a meter from the top. Usually easy to process and can be located on the surface itself. In some cases, a mineral can be discovered under groundwater. In this case, the team installs a special drainage to drain the water.

Winter is not an obstacle to mining. To avoid freezing of the soil, it is insulated with sawdust and other substances with low level thermal conductivity. The thickness of the insulation sometimes reaches 50 cm. Already mined clay is also protected from freezing. It is covered with a tarpaulin or other similar material that can hold desired temperature until the clay is delivered to the warehouse.

Clay in construction

IN construction industry clay began to be used from the first days of its discovery. Today the material is quite widely used for the construction of houses in the southern regions. Thanks to the properties of the fossil, the houses are cool in summer and warm and cozy in winter. To make blocks, they take only a little sand, clay and straw. After hardening it becomes durable construction material, which is not susceptible to any natural factors.

Which clay is better For the construction of houses, experts answer unequivocally. The most suitable is cement clay. Cladding tiles are also often made from this material. With the help of such finishing you can not only decorate the room, but also protect it from fire. After all, cement clay is also fireproof.

Clay dishes

Cutlery made of clay is not only beautiful, but also useful. The material is environmentally friendly. Do not be afraid that the dishes will release substances harmful to health when exposed to high temperatures. Many people associate the use of clay with the manufacture of plates, pots and vases. Today, dishes from this material are made on an industrial scale. Anyone can purchase a service from quality material, which can last for a long time.

Much more appreciated handmade. Entire exhibitions are organized where craftsmen can show off their products. You can also buy high-quality pottery here. The main thing is that the product is made in a single copy. But the price will be appropriate.

Clay modeling with children

Making various products using clay can be a lot of fun and a fun activity for a child. Modeling promotes mental development, improves motor skills of children's hands. The kid can show his imagination for his own pleasure. Parents will always tell you what can be made from clay.

Clay modeling requires careful preparation. It should be remembered that not all clothes can be washed away from minerals. And the child will definitely put stains. Therefore, the baby should be dressed in a work uniform and the table covered with oilcloth. What is the first thing you can make from clay? First of all, you should sculpt simple oval figures. These can be animals or funny people. With an older child you will be able to make a plate and spoon. After hardening, the product can be painted. It will look original and can be preserved for a long time. But it is worth remembering that clay without firing is quite fragile.

Use of clay in medicine

Even in ancient times people noticed beneficial features clays and began to use them for medicinal purposes. Some types of minerals have an anti-inflammatory effect. Due to this, they are used to treat various skin diseases. Clay quickly helps to cope with burns, acne and eczema. But you should never self-medicate. Selected species clays have different properties. Only a specialist can choose required material and apply it correctly to the sore spot. Without necessary knowledge and skills can only cause harm.

Clay is a mineral that is a source of many minerals, vitamins and microelements. Some types of rock can also be taken internally. Clay is an excellent source of radium. In this case, the body absorbs the amount useful substance which is necessary for normal life.

Clay can remove toxins from the blood and also normalize metabolism. Due to this, it is often used for various types of poisoning. The powder is taken orally in a small amount with water. But only certain types of clay can be used for medicinal purposes.

Clay in cosmetology

Many girls often use cosmetic clay to improve their appearance. The mineral can even out skin tone, rid the face of acne, and remove fat deposits from the thighs. Used for cosmetic purposes different kinds clay. They all have their own characteristics and properties.

For facial rejuvenation, the most commonly used mineral is white clay. The photos of women who used this product to improve their faces are impressive. Expression wrinkles are actually smoothed out, and pigment spots disappear completely. The substances are also perfect for girls with oily skin and large pores - information that can be read on the packaging. But it is still better to use any clay after consultation with a cosmetologist.

Applications of blue clay

This rock has good anti-inflammatory properties. It contains salts and minerals necessary for normal functioning. Blue clay masks should be made by people who are prone to skin rashes. With the help of a natural substance, acne and comedones are perfectly treated.

Blue clay can also be used to make your skin lighter. 10 procedures will help you for a long time get rid of freckles and age spots. In addition, it perfectly smoothes shallow expression wrinkles.

Green clay

This substance is also quite widely used in cosmetology. Green clay has excellent adsorbing properties. Thanks to this, it is possible to quickly cleanse the body of harmful substances and toxins. Clay can be applied to the face or the whole body.

Wraps using green clay are considered popular. The mineral helps restore the body's water balance and remove excess moisture. This property helps girls get rid of cellulite, as well as make their skin more even and smooth.

Red clay

Most optimal for people who have a tendency to allergic reactions, there will be red clay. This substance has a special color due to the content of copper and iron oxide. Only the extracted substance cannot be immediately used in cosmetology. Making clay for various masks is a labor-intensive process. WITH special attention It is red clay that is being prepared for use. The breed is cleaned of various harmful impurities that can harm the skin.

Red clay masks perfectly relieve redness and irritation of the skin. The material is also widely used in medicine. Red clay promotes faster healing and makes postoperative scars less noticeable.

Hi all!

You've probably seen that there are now a lot of jars and bags of cosmetic and medicinal clay on sale.

It is sold in stores, pharmacies, and specialized cosmetic stores.

What kind of clay is this and what healing effect can our skin get from interacting with it?

Let's figure out how cosmetic clay is useful for the face and body and consider all its types and properties ☺

From this article you will learn:

Cosmetic clay for face and body - properties and application

Clay is a polymer rock of volcanic origin, consisting of various minerals.

Cosmetic clay is a natural product that contains all the nutrients that our skin needs.

It contains mineral salts and very important trace elements:

• phosphorus,
• potassium,
• sulfur,
• iron,
• magnesium,
• calcium,
• manganese,
• cobalt,
• copper,
• nickel,
• zinc,
• vanadium,
• silicon and many others.

Today it has been scientifically proven that with the help of clay you can not only cleanse the body of toxins (natural cosmetics are an environmentally friendly adsorbent), but also harmonize the human biofield by returning magnetic-electric balance to the cells

How does clay affect the face and body?

Clay can improve the condition of your body's skin:

1. Clear,
2. Remove excess fat
3. Reduce sweating
4. Relieve irritation and itching,
5. Fill with trace elements and mineral salts

The main thing is to know and choose the right type of cosmetic clay that best suits your skin type.

Types of cosmetic clay for face and body

Clay occurs in nature in a variety of colors:

• white,
• green,
• yellow,
• red,
• blue,
• gray and even black.

You can tell by the color mineral composition clay, which in turn depends on the place of its origin.

Each type of clay has its own specific qualities, so it can be used in medicine and cosmetology for a variety of purposes.

White cosmetic clay or Kaolin

• What does it look like and what properties does it have?

White clay or Kaolin is a homogeneous white powder that has a yellow or grayish tint and is slightly greasy to the touch.

This is the most versatile and popular look cosmetic clay.

It is ideal for treating, cleansing, nourishing, rejuvenating and restoring the skin.

This is one of the best scrubs that can gently exfoliate dead epidermal cells.

• What skin type is it suitable for?

This clay is great for caring for oily, combination or inflamed facial skin.

It perfectly dries, cleanses, tightens the skin, eliminates excess fat, tightens pores well and gives a slight whitening effect.

Blue cosmetic clay or Bentonite

• What properties does it have?

Many people know the anti-inflammatory properties of blue clay.

It contains all the mineral salts and trace elements necessary for the skin.

Prevents the appearance of acne, heals wounds and evens out facial skin, smoothing out facial wrinkles and evening out the skin.

It also has a slight whitening effect that can lighten freckles and age spots.

• What skin is it suitable for?

Great for oily and problematic skin.

In addition, blue clay is used in folk medicine as a very effective means against baldness. To do this, it is diluted in a small amount of warm water and applied to the scalp, rubbing into the roots of the hair for 15 minutes, 3 times a week.

Green cosmetic clay

It has the widest application in cosmetology.

Thanks to iron oxide, this type of cosmetic clay has a rich dark green color.

This clay has powerful cleansing properties, increases blood circulation in the skin, thereby increasing its elasticity (turgor).

• How is it used and what skin type is it suitable for?

This type of clay is medicinal and can be used for some skin diseases (dermatitis, problem skin)

This clay perfectly restores the skin's hydrobalance, absorbs harmful components, and also perfectly softens and cleanses the pores of the face, eliminating oily shine.

Green cosmetic clay serves as the basis for cosmetics and is effectively used in the form of masks, wraps and various compresses.

Green clay can be mixed with any other type of cosmetic clay.

Red cosmetic clay

Red clay gets its color from a combination of iron oxide and copper.

• What properties does red clay have?

Due to the fact that its energetic properties are warm, it is best to apply it to the skin at winter time of the year.

It tightens aging and flabby skin well, improves blood circulation, and helps to increase the saturation of the facial skin with oxygen.

It is great for sensitive skin prone to allergic reactions (irritation, itching, peeling).

You can read more about red clay in this

Pink cosmetic clay

Pink cosmetic clay is formed by mixing white and red clay.

• What properties does pink clay have and what skin type is it suitable for?

It perfectly smooths out small wrinkles and tightens the facial contour.

Gently combats dry and irritated skin.

It relieves fatigue well, increases skin tone and elasticity.

This clay is ideal for any skin type.

Yellow cosmetic clay

• What properties does it have?

This clay relieves inflammation, improves complexion, tones and saturates the skin with oxygen.

Easily softens dead skin (especially on the elbows and legs and easily heals small cracks)

And also eliminates bad smell and increased sweating of the feet.

• What skin type is it suitable for?

It is very rich in iron and potassium and is ideal for caring for oily, combination, aging and dull skin.

Black cosmetic clay

Black clay contains strontium, quartz, iron, magnesium and calcium.

It is worth noting that black clay is capable of burning fat deposits and can be effectively used for anti-cellulite wraps, improving blood circulation and lymph flow.

It cleanses the skin very well.

This type of clay can perfectly absorb all harmful toxins and impurities from the skin. Helps tighten facial pores.

Suitable for normal, oily and combination skin.

Gray cosmetic clay

This type of clay is mined from the very depths of the seas.

Due to its moisturizing and toning properties, it is used for dehydrated, dry skin of the face and body.

How to apply cosmetic clay correctly?

Cosmetic clay is one of those cosmetic products that can be used in a wide variety of ways:

• scrub masks,
• compresses,
• wraps,
• applications,
• massage.

Compress or wrap with clay

Clay powder must be diluted with infusion of medicinal herbs or water (milk) to the consistency of sour cream and applied to cleansed skin of the face and body.

For the wrapping procedure, you need to wrap yourself in cling film and wrap yourself in a warm blanket for 1 hour.

Clay baths for the body

To take a bath with clay, you just need to dissolve cosmetic clay powder in water or herbal decoction, pour it into the bath and take it for 20-30 minutes (4-5 tbsp per bath)

Mask-Scrub made from cosmetic clay

It is very useful to make a mask from cosmetic clay once a week.

It not only evens out the surface of the skin, but also restores its color and normalizes blood circulation.

To do this, a small amount of powder is diluted with water or herbal infusion to form sour cream and applied to the facial skin along massage lines.

Massage with clay

It is useful to use some types of cosmetic clay.

To do this, add it in a small amount to body massage oil, perform a massage, and then wash it off under a contrast shower.

Cosmetic clay for the face - basic rules of use

Let's remember a few basic rules for using cosmetic clay:

1. Regularity of use (2-3 times a week).
2. Clay should be applied to a clean face or body after a shower.
3. It is necessary to wash off the clay by taking a contrast shower.
4. The first few procedures may be accompanied by a deterioration in the condition of the body’s skin and hair, due to the release of harmful components from the body.

How to make cosmetic face masks with clay?

So, the rules for making clay masks:

1. The base of any cosmetic clay mask consists of 0.5 tbsp of cosmetic clay and 0.5 tbsp of water or herbal infusion.
2. The mixture is applied to cleansed facial skin for 15-20 minutes. Wash off first with warm water and then with cold water.
3. If you have irritated skin, add 0.5 tsp of apple cider vinegar to the base of the mask.
4. If you need to moisturize your facial skin, add to the clay base in equal proportions: sour cream, milk, heavy cream, fruit pulp (watermelon, grapes, peach), vegetable oils (grape seed, jojoba), mineral water, aloe juice, egg yolk, 1-2 drops of essential oils.
5. For dry skin, you can add to the base: cottage cheese, protein, yogurt, yogurt.
6. For oily skin, it is good to add to clay, honey, lemon juice in proportions 1:1

Features of using cosmetic clay

It should be remembered that the darker the color of the clay, the better it will remove fat and effectively deal with acne (except rosacea).

For example, black cosmetic clay can completely eliminate acne, leaving your skin healthy and very clean!

Do not forget that clay, like any other component, can cause allergic reactions.

Where to buy high-quality cosmetic clay?

Real high-quality clay cannot be cheap.

You should not buy clay for cosmetic purposes for 15-20 rubles, it is of a very low degree of purification and may contain harmful salts of heavy metals, as well as sand, stones and can injure the skin when applied.

This one suits me very well French 100% green clay, this jar lasts me for six months. I make masks once a week and I really like how it “polishes” and evens out the skin.

I hope my post will help you do right choice in the variety of cosmetic clays and appreciate its magical effect on our skin.

Use this wonderful natural remedy, tell your friends at in social networks... Let your face be decorated with a healthy glow and smile, and not nasty pimples or wrinkles ☺

Alena Yasneva was with you, see you again!

/ Rock Clay

Clay is a rock, when dry it is like dust, but when wet it becomes plastic, soft, such that it can be sculpted, that is, given the desired shape. Clay happens various colors for example, red, blue, green, brown, but in most cases it is still gray.

The properties of clay are that it is plastic, fireproof, and waterproof. In many remote corners of our earth, unbaked clay is still used in the construction of their homes. Nowadays there are many various applications clay, for example:

Pottery production today consists mainly of bricks, tiles with various designs, pottery, and toys. A person working with such clay is called a potter. After the product has been given the desired shape, it needs to be painted, then the product is fired in a special oven. Clay is also part of cement, since cement is limestone + clay.

Clay is also widely used in medicine. Mud baths are very good for various diseases. Clay is added to various ointments. Clay would seem like dirt, dirt, but it's valuable product which humanity really needs.

Clay- fine-grained sedimentary rock, lumpy or dusty in a dry state and acquiring plasticity or becoming limp when moistened.

Clay composition

Clay consists of one or more clay minerals - illite, kaolinite, montmorillonite, chlorite, halloysite, or other layered aluminosilicates, but may also contain sand and carbonate particles as impurities. Alumina (Al2O3) and silica (SiO2) form the basis of the composition of clay-forming minerals.

The diameter of particles in clay is less than 0.005 mm; rocks consisting of larger particles are usually classified as silt. The color is varied and is mainly due to the coloring impurities of mineral chromophores or organic compounds. Pure clay mostly gray or white, but clay of red, yellow, brown, blue, green, purple and black is also common.

Origin

Clay is a secondary product formed as a result of the destruction of rocks during the weathering process. The main source of clay formations are feldspars, the destruction of which under the influence of atmospheric agents forms silicates of the group of clay minerals. Some clays are formed by the local accumulation of these minerals, but most are sediments from water flows that accumulate at the bottom of lakes and seas.

In general, based on origin and composition, the breed is divided into:
Sedimentary clays, formed as a result of the transfer to another place and deposition there of clayey and other products of the weathering crust. Based on their origin, sedimentary clays are divided into marine clays, deposited on the seabed, and continental clays, formed on the mainland.

Among the marine ones there are:
Coastal marine clay - is formed in coastal zones (turbulence zones) of seas, open bays, and river deltas. They are often characterized by unsorted material. They quickly change into sandy and coarse-grained varieties. Replaced by sandy and carbonate deposits along the strike. Such clays are usually interbedded with sandstones, siltstones, coal seams and carbonate rocks.

Lagoon clay - formed in marine lagoons, semi-enclosed with increased concentration salts or desalinated. In the first case, the clays are heterogeneous in granulometric composition, insufficiently sorted and wind together with gypsum or salts. Clays from desalinated lagoons are usually finely dispersed, thin-layered, and contain inclusions of calcite, siderite, iron sulfides, etc. Among them there are fire-resistant varieties.

Shelf clay - forms at a depth of up to 200 m in the absence of currents. They are characterized by a uniform granulometric composition and large thickness (up to 100 m or more). Distributed over a large area.

Among the continental ones there are:
Deluvial clay - characterized by a mixed granulometric composition, its sharp variability and irregular layering (sometimes absent).

Lake clay, mostly with a uniform granulometric composition and finely dispersed. All clay minerals are present in such rocks, but kaolinite and hydromicas, as well as minerals of hydrous oxides of Fe and Al, predominate in the clays of fresh lakes, and minerals of the montmorillonite group and carbonates predominate in the clays of salt lakes. Belongs to lacustrine clays best varieties refractory clays.

Proluvial, formed by temporary flows. Characterized by very poor sorting.
River - developed in river terraces, especially in the floodplain. Usually poorly sorted. They quickly turn into sands and pebbles, most often non-layered.

Residual clays - resulting from the weathering of various rocks on land, and in the sea as a result of changes in lavas, their ashes and tuffs. Down the section, residual clays gradually transform into parent rocks. The granulometric composition of the residual clay is variable - from fine-grained varieties in the upper part of the deposit to uneven-grained ones in the lower part.

Residual clays formed from acidic massive rocks are not plastic or have little plasticity; Clays formed during the destruction of sedimentary clay rocks are more plastic. Continental residual clays include kaolins and other eluvial clays. In Russia, in addition to modern ones, ancient residual clays are widespread - in the Urals, Western and Eastern Siberia, (there are also many of them in Ukraine) - of great practical importance. In the mentioned areas, mainly montmorillonite, nontronite and other clays appear on basic rocks, and on medium and acidic rocks - kaolins and hydromica clays. Marine residual clays form a group of bleaching clays composed of minerals of the montmorillonite group.

Practical uses of clay

Clays are widely used in industry (in the production ceramic tiles, refractories, fine ceramics, porcelain-faience and sanitary wares), construction (production of bricks, expanded clay and other building materials), for household needs, in cosmetics and as a material for artistic works (modelling). Expanded clay gravel and sand produced from expanded clay by annealing with swelling are widely used in the production of building materials (expanded clay concrete, expanded clay concrete blocks, Wall panels etc.) and how heat and soundproofing material. This is a lightweight porous building material obtained by firing low-melting clay.

This clay has the shape of oval granules. It is also produced in the form of sand - expanded clay sand. Depending on the clay processing mode, expanded clay of different types is obtained. bulk density(volume weight) - from 200 to 400 kg/m3 and above. Expanded clay has high heat and noise insulation properties and is used primarily as a porous filler for lightweight concrete, which has no serious alternative. Expanded clay concrete walls are durable, have high sanitary and hygienic characteristics, and expanded clay concrete structures built more than 50 years ago are still in use today. Housing built from prefabricated expanded clay concrete is cheap, high quality and affordable. The largest producer of expanded clay is Russia.

report an error in the description

Clay- a plastic natural material used in construction, folk crafts, treatment and healing of the body and in other areas of human life. It is this widespread use that is determined by certain qualities and properties of clay. And the properties of clay are largely influenced by its composition.

Application of clay

Clay is very accessible, and its benefits are invaluable, and therefore it has been used by people since ancient times. There are many mentions of this wonderful material in history textbooks of all countries of the world.

Construction. Currently, clay is used as a material for making red bricks. Clay of a certain composition is molded and fired using a certain technology to obtain a durable and inexpensive ingot - a brick. And buildings and structures are already being built from brick. In some countries and regions, clay is still used to build houses - mud huts; the use of clay is widespread in the construction of brick ovens, where clay serves as a binder (as cement). The same clay is also used for plastering stoves.

Medicine. Wellness and traditional medicine uses clay in the form of mud baths and masks. The whole point is to nourish the surface of the skin useful elements clay. Of course, not all clay will work here.

Souvenirs and dishes. I combine two large directions into one, since many examples of dishes are only of a souvenir nature. Plates, pots, jugs and vases are present in abundance in modern stores. Not a single fair is complete without the sale of clay souvenirs - smoky toys, whistles, signs, keychains and much more. You and I will try to create a lot of things ourselves.

Clay can be included in composition of other materials. Finely ground Chasovoyar clay, for example, is an element of artistic paints (gouache), sauce, pastels and sanguine. Read about this in the "Help to the Artist" articles.

Properties of clay

Color. Clay various compositions has many shades. The clay is called by its colors: red, blue, white... However, upon drying and further firing, the color can completely change. This is worth paying attention to when working with clay.

Plastic. It was the ability to deform and retain the shape given to it that allowed man to find the use of clay in his everyday life. It is worth noting here that everything depends on the consistency - the ratio of the amount of water, clay and sand. For various works different compositions are needed. So, for sculpting, sand may be completely unnecessary.

Hygroscopicity allows clay to absorb water, changing its viscosity and plasticity properties. But after firing, clay products acquire water resistance, strength and lightness. The development of technology has made it possible to obtain earthenware and porcelain, which are indispensable in the modern world.

Fire resistance. A property used more in construction than in artistic crafts, except for the firing of products. The firing technology is different for a particular clay composition. Closely related to drying and firing is the property of clay shrinkage or compressibility - a change in mass and size due to the removal of part of the water from the composition.

Clay composition

The properties of clay are determined by its chemical composition. Different types of clay have different chemical compositions. For example, red clay contains a lot of iron oxides. Clay basically contains certain substances - clay minerals - which are formed during various natural phenomena. The format of the article does not provide for consideration chemical properties and the composition of the clay, so I won’t go into detail.

The composition of clay suitable for use in folk crafts, as already mentioned, is determined by three the most important elements: clay minerals, water and sand.

The proportions of these elements can be changed, although it is much easier to add than to remove. So, for example, dry clay can be quickly dissolved, however, it is not at all easy to make clay as liquid as sour cream suitable for modeling. Sand is very easy to add, but removing it from the clay is a non-trivial task.

There are “lean” and “fat” clays. The “fat content” scale determines the plasticity coefficient, and the binding properties of the clay allows you to adjust the fat content by mixing it with others natural materials, for example, with sand. Lean clay has less plasticity, its binding force is weaker, but it shrinks less during drying and firing.

Clay deposits are found in varying states around the world. This ensured its use by artisans of different nationalities, and contributed to the emergence of such a variety of products and technologies.

Craftsmen have learned to control the behavior and condition of clay through various additions to the composition. This way you can thin the clay, elutriate it, give it greater fire resistance, and reduce shrinkage. As a result of such manipulations experienced master will be able to end up with a high-quality, highly artistic product.

Clay consists of one or more clay minerals - illite, kaolinite, montmorillonite, chlorite, halloysite, or other layered aluminosilicates, but may also contain sand and carbonate particles as impurities. Alumina (Al 2 O 3) and silica (SiO 2) form the basis of the composition of clay-forming minerals.
The diameter of clay particles is less than 0.005 mm; rocks consisting of larger particles are usually classified as silt. The color of clays is varied and is determined by Ch. in a way that colors them with impurities of mineral chromophores or organic compounds. Most pure clays are gray or white, but clays in red, yellow, brown, blue, green, purple and black are also common.

Origin

Clay is a secondary product formed as a result of the destruction of rocks during the process of weathering. The main source of clay formations are feldspars, the destruction of which under the influence of atmospheric agents forms silicates of a group of clay minerals. Some clays are formed by the local accumulation of these minerals, but most are sediments from water flows that accumulate at the bottom of lakes and seas.

In general, according to their origin and composition, all clays are divided into:

• Sedimentary clays, formed as a result of the transfer to another place and deposition there of clayey and other products of the weathering crust. Based on their origin, sedimentary clays are divided into marine clays, deposited on the seabed, and continental clays, formed on the mainland.
  • Among marine clays distinguish:
    • Coastal-sea - formed in coastal zones (turbulence zones) of seas, open bays, river deltas. They are often characterized by unsorted material. They quickly change into sandy and coarse-grained varieties. Replaced by sandy and carbonate deposits along strike. Such clays are usually interbedded with sandstones, siltstones, coal seams and carbonate rocks.
    • Lagoonal - formed in sea lagoons, semi-enclosed with a high concentration of salts or desalinated. In the first case, the clays are heterogeneous in granulometric composition, insufficiently sorted and wind together with gypsum or salts. Clays from desalinated lagoons are usually finely dispersed, thin-layered, and contain inclusions of calcite, siderite, iron sulfides, etc. Among these clays there are fire-resistant varieties.
    • Shelf - formed at a depth of up to 200 m in the absence of currents. They are characterized by a uniform granulometric composition and large thickness (up to 100 m or more). Distributed over a large area.
  • Among continental clays highlight:
    • Colluvial - characterized by a mixed granulometric composition, its sharp variability and irregular layering (sometimes absent).
    • Ozernye, b. parts with a uniform granulometric composition and finely dispersed. All clay minerals are present in such clays, but kaolinite and hydromicas, as well as minerals of hydrous oxides Fe and Al, predominate in clays of fresh lakes, and minerals of the montmorillonite group and carbonates predominate in clays of salt lakes. Lake clays include the best varieties of fire-resistant clays.
    • Proluvial, formed by temporary flows. Characterized by very poor sorting.
    • River - developed in river terraces, especially in the floodplain. Usually poorly sorted. They quickly turn into sands and pebbles, most often non-layered.
• Residual clays- clays resulting from the weathering of various rocks on land, and in the sea as a result of changes in lavas, their ashes and tuffs. Down the section, residual clays gradually transform into parent rocks. The granulometric composition of residual clays is variable - from fine-grained varieties in the upper part of the deposit to uneven-grained ones in the lower part. Residual clays formed from acidic massive rocks are not plastic or have little plasticity; Clays formed during the destruction of sedimentary clay rocks are more plastic. Continental residual clays include kaolins and other eluvial clays. In Russia, in addition to modern ones, ancient residual clays are widespread - in the Urals, in the West. and Vost. Siberia (there are also many of them in Ukraine) - of great practical importance. In the mentioned areas, clays predominantly montmorillonite, nontronite, etc. appear on basic rocks, and on medium and acidic rocks - kaolins and hydromica clays. Marine residual clays form a group of bleaching clays composed of minerals of the montmorillonite group.

Practical use

Clays are widely used in industry (in the production of ceramic tiles, refractories, fine ceramics, porcelain-faience and sanitary wares), construction (production of brick, expanded clay and other building materials), for household needs, in cosmetics and as a material for artistic works (modeling ). Produced from expanded clay clays By annealing with swelling, expanded clay gravel and sand are widely used in the production of building materials (expanded clay concrete, expanded clay concrete blocks, wall panels, etc.) and as a heat and sound insulating material. This is a lightweight porous building material obtained by firing low-melting clay. It has the shape of oval granules. It is also produced in the form of sand - expanded clay sand. Depending on the clay processing mode, expanded clay of varying bulk density (volumetric weight) is obtained - from 200 to 400 kg/m 3 and higher. Expanded clay has high heat and noise insulation properties and is used primarily as a porous filler for lightweight concrete, which has no serious alternative. Expanded clay concrete walls are durable, have high sanitary and hygienic characteristics, and expanded clay concrete structures built more than 50 years ago are still in use today. Housing built from prefabricated expanded clay concrete is cheap, high quality and affordable. The largest producer of expanded clay is Russia.

Literature

• Gorkova I.M., Korobanova I.G., Oknina N.A. and others. The nature of strength and deformation characteristics of clayey rocks depending on the conditions of formation and moisture. - Tr. Laboratory hydrogeol. Probl., 1961, issue. 29