Talc chemical properties. Talc is the most common material. The main physical characteristics of the mineral

Talc - Mg3 (OH) 2

Talc composition

The chemical composition of talc.

Contains admixtures of Fe (up to 2-5%), Al, Ca, Mn, Ni.

Origin of name. The name is ancient Arabic. origin. Synonym - steatitis, or wen.

Morphological features. Sheetish and scaly aggregates (talc schist), stellate accumulations, dense thin and hidden flaky rocks (talc stone, etc.), rarely fibrous masses (agalite) or tabular crystals, poorly faceted and easily split into thin plates and leaves.

The color in large-leaved secretions is light green, sometimes white with a yellowish, brownish tint; it can be both colorless and rather densely colored (to brown and dark green). Darker tones are characteristic of dense, contaminated aggregates such as talc stone. The color intensity depends on the content of impurity elements (especially Fe) or the presence of iron hydroxides.

Thin plates of light, iron-free varieties are characterized by transparency or translucency.

The luster of leafy talc is vitreous, with a pearly sheen on cleavage planes; in dense masses - dim shimmering.

Talc properties

• Fat to the touch.
• Cleavage is very perfect; the commissural leaves are flexible and slightly more resilient than those of pyrophyllite.
• Hardness 1 (standard of the lowest hardness in the Mohs scale); easily drawn with a fingernail and cut with a knife.
• Specific gravity 2.6-2.8.
• Inert to acids and alkalis.

Talc deposits

Origin and distribution. Quite widespread. The main rock-forming mineral of rocks called talc stone, steatite, wen, soapstone or pot stone. It is formed during hydrothermal processing of ultramafic rocks, dolomites, or as a result of the metamorphism of magnesium-rich sedimentary rocks.

Companion Minerals:

In deposits associated with ultramafic rocks - serpentine, carbonates (magnesite, sometimes ankerite, dolomite, calcite), also chlorite, actinolite (less often tremolite), iron oxides (magnetite, hematite), pyrite, residual minerals of the chromite group, tourmaline, apatite, epidote, fuchsite (chrome-containing green muscovite); in deposits associated with hydrothermal alteration or metamorphism of dolomites and dolomitic limestones (marbles) - calcite, dolomite, quartz, sometimes serpentine, thermolite. Deposits in the Urals: Shabrovskoye, Nizhne-Isetskoye and others in the Sverdlovsk region, also in the Miass district of the Chelyabinsk region.

Stable on the surface of the earth; during hydrothermal alteration, it can pass into a mixture of magnesite and quartz.

diagnostic signs. It differs from aggregates of micas, hydromicas, and clay minerals by very low hardness, pearly luster on perfect cleavage planes in foliar segregations, light color, oiliness to the touch, and also by the association of minerals and rocks. It differs from pyrophyllite with the help of chemical reactions (see pyrophyllite).

Practical value. Iron-free finely ground talc is widely used for medical and hygienic purposes; in perfumery and cosmetics; also as a solid lubricant; in ceramic production. Talc powder is used as a filler in the manufacture of rubber, paper, paints, soap, soft pencils for glass, metal, fabric; in the textile business as a bleaching material for cleaning cotton; for electrical insulators in high voltage networks; in the production of glazes, acid- and alkali-resistant vessels, drainpipes. Talcum stones, especially those containing magnesite, combine refractory, acid and alkali resistance, heat and electrical insulating properties.

Table. Chemical composition and physical properties of talc for the cable industry.

/ Mineral Talc

Talc is a common mineral, silicate, pyrophyllite-talc group.

Varieties:

Agalite (fine-fiber talc),
noble talc (transparent light talc),
Willemseit (nickel talc),
Minnesotaite (ferrous talc),
Steatite (wen) (dense massive talc)

For the first time, a description of a stone under the indicated name was found as early as 1546. Talc was used by George Agricola - the great scientist of the Renaissance. He applied the name "talc", describing the properties of the mineral and calling it pure and white. Even then, it was used in stone-cutting work, but only in some compounds and varieties that could be found in descriptions under the designations "soapstones", "wen", "only chlorite" and "steatite".

Origin

The origin of talc is associated with metamorphism. In this case, both the processes of thermometamorphism and hydrothermal processes (hydrothermal-vein - when filling voids and hydrothermal-metasomatic when replacing) can be involved. Most often, talc occurs during hydrothermal alteration of ultramafic rocks after serpentinization. It is formed during metamorphism after dolomites and clays.
Talc is a rock-forming mineral of talc schists and listvenites.

Special properties: talc - acid-resistant; greasy to the touch; flexible but not stretchy.

Place of Birth

In Russia, the Shabrovskoye talc-magnesite and Miass talcite deposits are being developed in the Middle Urals, the Onotskoye deposit of steatite (solid) talc (Eastern Sayan); the West Baikal talcon-bearing province was identified. Large deposits are known abroad in Canada (Maidock), the USA (Gavernour), France (Luzenac), etc.

Brumado, Bahia, Brazil - record crystals of talc (up to 4-5 cm!), covered with quartz // see. Min. Record: 1) 1987, 9, 204 2) 1992, 23, 274, 276

Talc is a common mineral found in Antarctica and the Mid-Ocean Ridge of the Atlantic Ocean; Australia, Austria, Algeria, Argentina, Afghanistan, Bulgaria, Bolivia, Brazil, Burkina Faso, Bhutan, UK, Hungary, Germany, Greenland, Greece, Zimbabwe, Indonesia, Iran, Spain, Italy, Kazakhstan, Cameroon, Canada, Colombia , both Koreas, Cuba, Madagascar, Mexico, Mongolia, Namibia, Norway, Oman, Pakistan, Paraguay, Peru, Poland, Portugal, Saudi Arabia, Slovakia, USA, Turkey, Chile, Switzerland, Sweden, South Africa, Japan and other countries .

Practical value

Talc is used for the manufacture of refractory materials, in metallurgy, in the textile, paper and chemical industries, and in medicine.
Steatite is used in the manufacture of various crafts. Powder prepared from talc or based on it has been widely used since ancient times and is still widely used as a powder for skin in medicine (a well-known baby powder is pure talc, but it has undergone a screening process of ferruginous rocks), as well as in everyday life to prevent sticking and friction of contacting surfaces ( in rubber gloves and other products, shoes, etc.). As a filler, it is used in rubber, paper, paint and varnish and other industries (in medical and perfumery and cosmetics). In ceramics (especially radio-insulating). Registered in the food industry as a food additive E553b. It is harmless and also not absorbed by the body. In a notorious "magical practice," talc was used to make potions that some believed could restore youth and beauty; these were various creams and ointments that acted on the skin as cosmetics, but nothing more.

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Mineral Properties

Talc is the most common soft mineral, which in its pure form has a white tint. The main color of the mineral is reflected in its name, which in translation from the ancient Arabic language means "pure, white." A palette of yellow-green, gray, pink, golden and brown-brown shades is provided by impurities of iron, aluminum, calcium, chromium, manganese and nickel.

Pure talc is a magnesium silicate with a complex chemical composition (Mg3) that can vary in stone varieties. Considered the softest mineral on the Mohs scale, talc has a greasy sheen and becomes slippery when wet. For this property, he was nicknamed "soapstone".

Dmitry Thessalonica, an icon made of talcum powder. Size 31.4 x 26.4 cm

The mineral is distinguished by perfect cleavage, on the planes it has a mother-of-pearl luster. An opaque mineral in thin layers can be transparent, resistant to acids, similar in crystal structure to mica.

Talc is considered a mineral with an ancient origin. On the territory of Egypt, archaeologists have found necklaces and amulets, the history of which goes back to the 4th century BC. In the countries of the East, the mineral was used to imitate jade. The world knows a unique carved icon depicting St. Demetrius of Thessalonica, which, despite the fact that it was made in the 11th century, has retained its original appearance to the present day. The first scientific studies of talc in 1546 were carried out by the great scientist George Agricola.

Varieties of talc

Mineralogists distinguish several varieties of talc, differing from each other in impurities and structural features:

• Steatite - talc with a massive dense structure, also called "wen";
• Minnesotaite is a brown-colored mineral, in which magnesium is displaced by iron in an amount of 50 to 80%;
• Agalite - talc, the crystals of which outwardly resemble asbestos due to tangled or parallel-arranged fibers in the crystal structure;
• Willemseit - a stone of blue and green shades with a predominance of nickel over magnesium in the chemical composition;
• Noble talc - amazing translucent or white crystals, characterized by high density, susceptibility to processing and polishing.
• Talcochlorite is a type of mineral in which chlorite acts as an impurity to talc.

Mineral deposits

magical properties

Application of talc

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Probably, everyone at least once in their life used talc for one purpose or another. However, talc is a mineral or This stone has a number of specific properties. Due to this, it is used both in cosmetology, and for the production of children's skin care products, and in industry (production of paints and varnishes, mechanical engineering, etc.)

The chemical composition of talc

Talc is hydrous magnesium silicate. Its chemical formula is approximately as follows: Mg3Si4O10(OH)2. This composition may have variations, since part of the silicon is replaced in some cases by aluminum, titanium, magnesium - iron or manganese. It should be noted that talc is a mineral that is almost insoluble in water and acids. The amount of impurities depends on the place of its extraction. It has long been mined in Egypt, around China. A high-quality mineral is also found in Poland, the Czech Republic, and France. In Russia, the main deposits are located in the Urals, in the Baikal region, the Krasnoyarsk Territory. This mineral is formed under conditions of metamorphism. The necessary conditions for the formation of talc are a temperature of about 400 ° C, a sufficient amount of water (after the transformation of minerals from rocks rich in iron and magnesium). Due to its characteristics, talc is a mineral of certain rocks. There are several types of talc.

Varieties of the mineral

Depending on the structural features and the presence of certain impurities, the following types of talc are distinguished. Agalite has a parallel (or tangled) arrangement of crystal fibers. Minnesotaite is a mineral that is closer to brown in color (due to the presence of iron, which replaces magnesium). Steatite has a dense structure. It is also called "fat". The presence of nickel in the composition is characteristic of willemseite. The color of this stone is blue or greenish. Talcochlorite has chlorite as an impurity. Often there is noble talc. It is a stone of high density, translucent (or slightly white). Such a mineral lends itself well to processing.

The main physical characteristics of the mineral

This stone has a color from translucent to brown. In powder, its color is white. Talc is the softest mineral, its hardness is one unit. The texture of the material resembles soap, it is slightly greasy to the touch. Elasticity is low, although it bends easily. Talc is a poor conductor of electricity and heat. The mineral adsorbs water well and is non-toxic. Can be sterilized at 160°C (at least one hour).

Talc in medicine

Talc is widely used in the manufacture of medicines. It can be found in many capsules and tablets. However, its concentration in this case should not exceed 30%. Talc is not recommended to be taken orally at elevated body temperature. Also contraindications are diseases of such internal organs as the stomach, spleen. Pregnant and lactating women should be especially careful with preparations containing this mineral. Talcum stones heated to a certain temperature are used to warm certain areas of the body. Talcum powder is widely used as an external agent. In this case, its concentration is allowed in the range of 90-99%. Talc is a product that perfectly removes excess moisture, thus protecting the baby's delicate skin from irritation. However, it is worth considering this point: prolonged inhalation or use of the powder of this mineral can provoke problems with the respiratory system, changes in tissues.

Features of powder for children

Since talc is a powder that comes into direct contact with the baby's skin, it must be sterilized without fail. In addition to this mineral, the composition includes starch. Also, some manufacturers may use ingredients such as rice starch, corn flour. It is worth avoiding powders that have a pungent odor, a heterogeneous structure. There are the following types of cosmetics: powder powder and liquid talc. The powder has good deodorizing and antiseptic properties. However, when used, the child may inhale some of it. Liquid talc is easy to use, when applied to the surface of the skin, it turns into a powder and absorbs excess moisture. Due to its consistency, talc does not roll into lumps. However, its cost is slightly higher than that of ordinary powder. Experts recommend using talcum powder as a powder from the second month of a child's life. Do not apply it directly to the skin. It is best to first pour on a cotton pad or your own palm, and only then apply with light powdery movements between the folds of the baby's skin.

The use of talc in cosmetology

In almost all eyeshadows, you can find a substance such as talc in the composition. It is a natural adsorbent that allows makeup to stay on the skin longer. Also, this powder is introduced into the composition and face creams. Such cosmetics help the skin to remain soft, smooth, dry. Talc is able to absorb all kinds of chemicals, toxins from the surface of the epidermis. As a result, the skin receives additional protection from damage. Some studies suggest that this mineral can prevent the growth and reproduction of certain bacteria (for example, typhoid fever). Very often, talc is used in the production of dry deodorants. It is also a component of face masks. There are certain requirements for the powder. Firstly, it must be thoroughly cleaned of impurities and microorganisms, and odorless. Secondly, there are limitations regarding particle sizes. In some cases, they should not be too small so as not to clog the pores of the epidermis.

Talc is what kind of material for modern industry?

In addition to medicine and cosmetology, talc is used in many industries. They cover all kinds of products made of rubber, plastic, rubber to prevent them from sticking together. Talc is also used in the food industry (as a filler, additive). The paper industry also uses this material. Talc-coated paper absorbs ink very well. It is in demand in government agencies (for especially important documents). Very often chalk is replaced with compressed talc. It makes good marks, it is easier to remove from fabrics. Due to its heat and electrical insulating properties, the mineral is used in the ceramic industry (to increase resistance to high frequency radiation).

With the approach of summer time, each of us thinks about how to avoid or minimize increased sweating, because in addition to an unpleasant visual effect, excessive body hydrosis greatly reduces the quality of life. Various means of protection come to the fore, among which talc for the body can be mentioned. Today we will try to answer: why do we need talc for the body, how to use it correctly?

What is talc extracted from?

In fact, natural talc is a complex crystalline substance, which includes magnesium, silicon and oxygen. In the state of aggregation, these are large crystals of white, greenish or pinkish color. The fragile natural mineral is quite easy to process and easily turns into powder. The most commonly used for cosmetic purposes is a processed and refined mineral of a snow-white color.

To the touch, the processed product resembles loose greasy powder. First discovered by Michael Faraday, such a mineral began to be actively used to eliminate diaper rash in infants. Later, attention was paid to the fact that rubber and rubber products sprinkled with talc retain their original qualities longer.

What is body talc used for?

Only after many decades cosmetologists paid attention to this bulk substance. It is talc that is the basis for the production of shadows and compact powder, without which specialized scrubs for the face and body, mineral soap are not made.

Recently, it has been flavored with various substances and used as a protective agent for excessive sweating. Interestingly, you can use aromatic talc not only in the summer, but all year round.

For what purposes is it used?

• Curvy women use it to eliminate diaper rash and give a delicate fragrance to the body.

• Sufficiently fine grinding of the mineral makes it possible to use it as a powder. Most often it is applied to the décolleté and armpits. At the same time, the skin becomes pleasant, and perspiration does not resume on the treated areas throughout the day.

• Some apply it to the inner side of the thighs (this is true for overweight women), the back area between the shoulder blades, feet (if there is an unpleasant smell of legs).

• Often the remedy is applied to the palms with excessive sweating.

Talc is the only natural mineral that has an antistatic effect. It is enough to treat the legs with the product - no clothes will stick to them. To do this, it is enough to apply talcum powder to the surface of the body with a soft puff, wait for a while. After two or three minutes, you need to remove excess fragrant powder by gently blotting the treated areas with a soft towel.