Rock salt- rock salt, Steinsalz (often also used to denote a rock consisting of halite), table salt - Kochsalz, sodium chloride- sodium chloride, lake salt, self-planting salt, ice salt, blue salt (for blue halite), partially hairy salt - Faserzalz, β-halite - β-halite (Panike, 1933), saltspar - saltspar (Murzaev, 1941) - coarse-crystalline secretions.
Crackling salt (Lebedev, Textbook of Mineralogy, 1907) - salt containing inclusions of gases, crackling when dissolved, falcon salt (Lebedev, ibid.)
- local name used in Yakutia, martinsite - martinsite, described by Karsten (1845) - halite from Stasfurt with an admixture of MgSO 4, natrikalite - natrikalite (Adam, 1869) - a mixture of halite and sylvite from Vesuvius, kallar - kallar (Dana, 1892)
- impure salt from India, Zuber - Zuber is a halopelite rock cemented with halite. Guantajayite - halite containing up to 11% silver, may be a mixture (Raimondi, 1876).
The English name of the mineral Halite is Halite
Origin of the name halite
The mineral is named from the Greek “als” - salt (Glocker, 1847).
Chemical composition
Chemical theoretical composition: Na - 39.34; Cl - 60.66. The composition of the very pure material corresponds to the theoretical one. Contains Br as an isomorphic impurity (up to 0.098%). The following impurities were also noted: He, NH 3, Mn, Cu, Ga, As, J, Ba, Tl, Pb. K, Ca, SO 3 are often detected due to the admixture of sylvite and gypsum.
Crystallographic characteristics
Syngony. Cubic (3L 4 4L 3 6L 2 9PC).
Class. Hexoctahedral.
Crystal structure
In the structure, Na and Cl atoms alternate uniformly at the sites of a simple (primitive) cubic lattice with a 0 = 2.82 A; in view of the difference between Na and Cl, we need to talk about two face-centered lattices (Na and Cl) with a 0 = 5.64 A, inserted into one another. Since the Cl ionic radius is significantly larger than the Na radius, the structure can be represented as a dense cubic packing of Cl atoms; all octahedral voids contain Na atoms. The coordination number of both Cl and Na is 6, the coordination polyhedron is an octahedron. Perfect cleavage along the faces of the cube is due to the fact that these planes are uniformly populated with cations and anions and are therefore electrically neutral. The ionic type of bond predominates.
Main forms: Main forms: a (100), o (111).
Form of being in nature
The appearance of crystals. The crystals are cubic, very rarely octahedral, sometimes reaching significant sizes. Cubic crystals of NaCl are formed from neutral solutions, octahedral crystals are formed from active, acidic or alkaline solutions. Very characteristic skeletal formations are fragile dull white hollow pyramids, “boats”, floating on the surface of the brine with the tip down; walls
boats are usually stepped, often bearing a scar or “suture” formed as a result of growth from the ribs along the walls towards each other. The boats are usually zonal as a result of the uneven arrangement of mother liquor inclusions, which usually form chains parallel to the faces of the cube. Often the boats are deformed and grow together. Skeletal crystals with a herringbone structure, the so-called “salt teeth,” are also found. Their peculiar appearance is due to the uneven distribution of inclusions, which is caused by a change in the growth rate under conditions of uneven supply of substances when the rate of brine evaporation changes.
Cubic crystals with funnel-shaped and concave faces are known. Sometimes the crystals are curved or have a distorted (rhombohedral or lamellar) shape due to growth under directed pressure conditions. Lenticular crystals grown in the clay were also noted, oriented with a third-order axis perpendicular to the layering of the clay. The edges of the crystals are often smooth and shiny, sometimes stepped or pitted. Etching figures corresponding to the hexoctahedral class are formed even when exposed to humid air. Etching figures on artificial crystals obtained by acetic acid, change their shape depending on the impurities added to acetic acid.
Doubles according to (111) were obtained only artificially from solutions containing significant amounts of MnCl 2, CaCl 2, CoCl 2. Mechanical twins are obtained by non-uniform compression at a temperature of 500-600°.
Rock salt crystals are often symmetrically or asymmetrically zoned as a result of uneven distribution of inclusions or color. Turbid areas are often located at the periphery of the crystals, closer to the tops and edges, i.e., in the directions of the most rapid growth crystals.
Aggregates. Aggregates from fine-grained to gigantic-grained are typical; Individual crystals and druses are not uncommon. It also forms parallel fibrous aggregates, sinter crusts, stalactites, fluffy deposits, crusts, and efflorescences.
Physical properties
Optical
Color. Colorless and often white, gray to black, red, brown, yellow, blue (sky blue to dark indigo), violet, mauve to dark purple; occasionally green.
The gray color is often caused by clay inclusions; black and brown, disappearing when heated - an impurity organic matter. Brown and yellow tones are sometimes associated with an admixture of iron compounds, in particular minute needles of hematite; in the latter case, the color is usually distributed unevenly or streakily. The green color can be caused by inclusions of Douglasite, in this case in air halite turns brown from the surface. Blue, violet and yellow colors that disappear in light are caused by exposure to radioactive radiation. The source of β-radiation in salt deposits is K4o and the accompanying radioactive Rb, which is confirmed by the repeatedly noted fact that halite turns blue in the vicinity of sylvite and other potassium salts, as well as laboratory studies.
The nature and intensity of staining is determined by the amount of β-radiation received by the sample and its sensitivity to radiation. The latter depends on many reasons, the most important of which are the following:
1) the degree of deformation of the lattice and the presence of certain stresses in it;
2) the amount and nature of impurity elements in the irradiated material, for example, an increased content of Ca was noted in blue salt, and Cu in violet salt; the total amount of impurities in purple and blue salt exceeds the amount in yellow salt; Neutral Na atoms were found in blue salt from Solikamsk
3) growth rate of the colored crystals. Very often, the blue color is distributed unevenly in crystals due to the locality of irradiation or the sensitivity of the crystals to it: in the form of zones parallel to the faces of the cube, irregular areas isolated from each other, edges, spots, winding stripes, etc. The colored areas themselves differ from each other from each other by a structure discernible under a magnifying glass: reticular, dotted-reticulate, dashed, spotted, zonal, spiral, etc. Sometimes this phenomenon is caused by the fouling of colored skeletal crystals with colorless salt.
The color caused by radioactive radiation disappears when heated in light, but the samples retain increased colorability.
- Trait white to colorless
- Glass shine.
- The cast on a stale surface is greasy to greasy.
- Transparency. Transparent or translucent.
Mechanical
- Hardness 2, slightly different when scratching along the edge and along the diagonal of the cube. The average hardness on a cube face is less than on an octahedron face. The hardness of dark blue salt is significantly higher. Microhardness 18-22 kg/mm 2. It is easiest to polish along the edges of the cube, hardest along (110) and worst of all along (111). The impact figure looks like a four-ray star made of cracks in the plane of the rhombic dodecahedron.
- Density 2.173, often fluctuates due to the presence of inclusions, for example, salt from Kalush from 1.9732 to 2.2100; There was an increase in density with increasing intensity of blue color
- Cleavage according to (100) is perfect, according to (110) imperfect (the fine structure of the cleavage planes was studied under an electron microscope)
- The fracture is conchoidal.
It is quite fragile, but when heated, its ductility increases significantly (in a hot saturated solution it can be easily bent by hand); becomes plastic also under prolonged unilateral pressure (about the degree plastic deformation halite can be judged by the optical density values in the region of 380-600 tpts, which depends on the degree of light scattering in the deformed areas).
Chemical properties
On salty halite taste. Easily dissolves in water (35.7 g in 100 cm3 of water at 20°). Solubility depends little on temperature, increasing by 7 g from 0 to 100°; decreases significantly if the solution contains CaCl 2 or MgCl 2 ; increases noticeably with increasing pressure. Dissolution is accompanied by significant heat absorption. Poorly soluble in alcohol (0.065% at 18.5°).
With AgNO 3 it reacts with Cl.
Other properties
Halite is hygroscopic, but does not melt in air.
Non-conductor of electricity. Dielectric constant 5.85. Diamagnetic When NaCl crystals were rubbed or squeezed, triboluminescence was observed. Fluoresces red when containing Mn. The glow of crystals activated X-ray irradiation, heat treatment. It has great transparency in the infrared region of the spectrum.
Melting point 800°. When heated, the refractive index decreases (to 1.5246 at 425°), and blue and purple salts become discolored.
Artificial acquisition.
Easily obtained by precipitation from aqueous solution. Water-clear crystals can be obtained by adding FeCl 3 or strong acids and bases. It is also formed during the sublimation of sodium chloride. There are known methods for producing whiskers.
It is not isomorphically miscible with KCl at ordinary temperatures; isomorphic mixtures were obtained only with rapid cooling of the melt. At temperatures above 500°, a series of double salts are formed, the refractive indices of which change in direct proportion to the content of the components; when cooled, they decompose into halite and sylvin. Many physicochemical aqueous systems with NaCl have been studied.
Diagnostic signs
Similar mineral- sylvin.
It differs from other water-soluble salts in its salty (but not bitter) taste. Differences from sylvin. Recognized by the cubic shape of the crystals, perfect cleavage along the cube, and low hardness.
Satellites. Silvin, gypsum, anhydrite.
Mineral Change
Halite is easily dissolved by water, and in place of its excretions, voids remain, sometimes retaining imprints of the finest sculpture of crystal faces. Often such voids are filled with marl, clay, gypsum, dolomite, anhydrite, celestine, polyhalite, quartz, hematite, pyrite. During metamorphism, halite from salt deposits recrystallizes, as a result of which the transparency of its grains and the size of single crystals increase, and their orientation also changes.
Mineral and chemical composition
Salt rocks are chemical sedimentary rocks consisting of halide and sulfate compounds of sodium, potassium, magnesium and calcium that are easily soluble in water (Table 12-VI).
Most salt rock minerals are sensitive to changes in pressure and temperature, as well as the concentration of solutions circulating through them. Therefore, during fossilization and the early stages of weathering, a noticeable change in the mineralogical composition of salt deposits occurs and structures characteristic of metamorphic rocks develop in them.
In the salt layers themselves, the admixture of clastic particles is usually very small, but in salt-bearing strata taken as a whole, interlayers of clayey rocks are in most cases an obligatory element.
Rocks transitional between salt, clay and carbonate are called salt-bearing clays and salt-bearing marls. When mixed with water, clays form a sticky and quite greasy, but non-plastic mass. Sediments consisting of clay minerals and gypsum are called clay gypsum. They are found among Quaternary deposits of arid regions.
Various finely dispersed impurities play a major role in salts. These include compounds of fluorine, bromine, lithium, rubidium, rare earth minerals, etc. Also characteristic is the presence of impurities of dolomite, iron sulfides or oxides, organic compounds and some other substances.
Some salt rocks are clear-layered due to changes in the composition of salts deposited throughout the year. For example, in the thickness of the rock salt of the Verkhnekamsk deposit of the Western Urals, according to M.P. Viehweg, the composition of the annual layer includes the following layers: a) clayey-anhydrite, 1-2 mm thick, apparently appearing in the spring; b) skeletal-crystalline halite, thickness from 2 to 7 cm, formed in summer; c) coarse- and medium-grained halite, usually 1 to 3 cm thick, formed in autumn and winter.
Salt rocks Main types of rocks
The most common types of salt rocks are:
a) gypsum and anhydrite;
b) rock salt;
c) potassium-magnesium deposits.
Gypsum and anhydrite. IN pure form the chemical composition of gypsum corresponds to the formula CaSC>4-2H20; then it contains 32.50% CaO, 46.51% SOe and 20.99% HgO. Based on the nature of the crystals, the following types of gypsum are distinguished: a) coarse-crystalline sheet; b) fine-fiber with a silky sheen (selenite), especially typical for gypsum veins; c) granular; d) earthy; e) spectacled porphyry structure." The layers of gypsum are painted pure white, pink or yellowish.
Anhydrite is anhydrous calcium sulfate - CaSCU. Chemically pure anhydrite contains 41.18% CaO and 58.82% EO3. It is usually found in the form of granular masses of a bluish-gray color, less often - white and reddish. The hardness of anhydrite is higher than the hardness of gypsum. Gypsum and anhydrite often contain admixtures of detrital particles, clay minerals, pyrite, sulfur, carbonates, halite and bituminous substances.
Very often, even in small areas of rock, interlayering of gypsum and anhydrite is observed. In general, anhydrite in the surface areas of the earth's crust (up to 150-300 At) usually transforms into gypsum, experiencing a significant increase in volume. In deeper zones, on the contrary, gypsum becomes unstable and turns into anhydrite. Therefore, gypsum and anhydrite often occur together, and replacement occurs along cracks, sometimes microscopically small.
Due to frequent recrystallization, heteroblastic and granoblastic structures are typical for gypsum and anhydrite, marked by a jagged arrangement of grains of sharply different or approximately the same size. Randomly squamous and fibrous structures are also often observed. The structure of gypsum and anhydrite is a good indicator of the conditions of their transformation, but not precipitation.
Gypsum and anhydrite deposits can be primary or secondary.
The primary formation of these rocks occurs in lagoons and salt lakes during the evaporation of the waters in them in a hot, arid climate. Depending on the composition and temperature of the evaporating water, either gypsum or anhydrite precipitates into the residue. "
Secondary accumulations of gypsum occur in the process of epigenetic transformation of anhydrite. It is generally accepted that most large deposits of gypsum arose precisely in this way. When gypsum is reduced with bitumen, free sulfur is formed, the deposits of which are usually confined to gypsum-anhydrite strata.
Practical use. The main area of application of gypsum is the production of binders and the manufacture of various products and building parts from them. In this case, the ability of gypsum to partially or completely lose crystallization water when heated is used. When producing building gypsum (alabaster), the gypsum is heated to 120-180°, followed by grinding into a fine powder. Building gypsum is a typical air binder, i.e., when mixed with water, it hardens and retains its strength only in air.
For the production of building gypsum, rocks containing at least 85% CaS04-2H20 are used.
Gypsum is also used for the preparation of gypsum and anhydrite cement used in construction work, as well as as an additive to Portland cement to regulate its setting time.
Gypsum is used in the paper industry as a filler in the production of high-grade writing paper. It is also used in the chemical industry and agriculture. Clay-gypsum is used as a plastering material.
Anhydrite is used in the same industries. In some cases, its use is significantly more profitable, since it does not require dehydration.
Rock salt. Rock salt is composed mainly of halite (NaCl) with some admixture of various chloride and sulfuric acid compounds, clay particles, organic and ferrous compounds. Sometimes the amount of impurities in rock salt is very small; in these cases it is colorless.
Rock salt layers are usually associated with layers of gypsum and anhydrite. In addition, rock salt deposits are an obligatory member of the potassium-magnesium salt-bearing strata.
In rock salt, ribbon layering is often observed, marked by alternation of purer layers and layers contaminated with impurities. The occurrence of such layering is usually explained by seasonal changes in the conditions of salt deposition.
Practical use. Rock salt is used as a seasoning for human and animal food. Salt used for food must be white, contain at least 98% NaCl and must be free of odor and mechanical impurities.
Rock salt is used in the chemical industry to produce of hydrochloric acid, chlorine and sodium salts. It is used in ceramics, soap making and other industries.
Potassium-magnesium salt rocks. The rocks of this group are composed mainly of sylvite KS1, carnallite KS1- MgCb -bNgO, polyhalite K2SO4 MgSCK- 2CaS04 2HgO, kieserite MgSCK-H2O, kainite KS1 MgS04 ZH2O, langbeinite K2S04-2MgSC>4 and epsomite MgSCK-TH K.O. Of the minerals that do not contain potassium and magnesium, these rocks contain anhydrite and halite.
Among the potassium-magnesium salt-bearing strata, two types are distinguished: strata poor in sulfate compounds and rich in them. The first type includes the Solikamsk potassium-magnesium deposits, the second - the Carpathian salt-bearing stratum, potassium deposits in Germany. Among the potassium-magnesium rocks, the following are the most important.
Sylvinite is a rock consisting of sylvite (15-40%) and halite (25-60%) with a small amount of anhydrite, clayey substances and other impurities. Typically, it exhibits clear layering, expressed by alternating layers of sylvite, halite and clayey anhydrite. The color of the rocks is determined mainly by the color of the sylvite grains, which is most often milky white (due to small gas bubbles) or reddish and red-brown. The latter type of color is due to the presence of finely dispersed hematite confined to the edges of the grains.
Silvin has a hot, salty taste and is much softer than halite (when passed over the surface with a steel needle, it gets stuck in it).
Carnallite rock is composed predominantly of carnallite (40-80%) and halite (18-50%) with a small amount of anhydrite, clay particles and other impurities. Carnallite is characterized by a burning sensation salty taste and inclusion of gases (methane and hydrogen). When a steel needle is passed over the surface of the crystals, a characteristic crackling sound is heard.
Solid salt is a sylvite-containing rock with a large amount of sulphate salts of kieserite. In the Carpathian deposits, solid salt contains sylvite, kainite, polyhalite, kieserite, halite and some other minerals.
Cainite rock consists of kainite (40-70%) and halite (30-50%). In some deposits there are also rocks composed of polyhalite, kieserite and other salt minerals.
Practical use. Potassium-magnesium salt rocks are used mainly for the production of fertilizers. Of the total amount of mined potassium salts, about 90% is consumed by agriculture and only 10% is used for other purposes. The most common types of fertilizers are unenriched sylvinite and solid salt, as well as their mixtures with technical potassium chloride obtained as a result of the enrichment of natural potassium raw materials. "
Magnesium salt rocks are used to obtain magnesium metal.
The satellites of salt-bearing strata are salt brines, which are often the object of industrial production.
Origin. The bulk of salt rocks are formed chemically due to the evaporation of true solutions in hot climates.
As the work of N.S. Kurnakov and his students showed, as the concentration of solutions increases, salts precipitate in a certain sequence depending on the composition of the original solution and its temperature. For example, precipitation of anhydrite from pure solutions is possible only at a temperature of 63.5°, below which it is not anhydrite that precipitates, but gypsum. Anhydrite precipitates from solutions saturated with NaCl already at a temperature of 30°; at an even lower temperature, anhydrite precipitates from solutions saturated with magnesium chloride. As the temperature increases, the solubility of various salts changes to varying degrees (for KS1 it increases sharply, for NaCl it remains almost constant, and for CaSCK it even decreases under certain conditions).
In general, when the concentration of solutions similar in composition to modern sea water increases, carbonates, gypsum and anhydrite precipitate first, then rock salt, accompanied by calcium and magnesium sulfates, and, finally, potassium and magnesium chlorides, also accompanied by sulfates and halite.
Evaporation is necessary for the formation of salt deposits. huge quantities sea water. So, for example, gypsum begins to precipitate after the evaporation of approximately 40% of the initially taken volume of modern sea water, rock salt - after the evaporation of approximately 90% of the initial volume. Therefore, for the formation of thick layers of salt, it is necessary to evaporate a very large amount of water. Note that, for example, for the formation of a gypsum layer with a thickness of only 3 m, it is necessary to evaporate a column of sea water of normal salinity, with a height of about 4200 m.
By the time the potassium salts precipitate, the volume of the brine becomes almost equal to the volume of the salts precipitated before. Therefore, if there is no influx of sea water into a reservoir, then, following M. G. Valyashko, we must assume that the precipitation of potassium salts occurred in the so-called dry salt lakes, in which the brine impregnates the salt deposits. However, ancient potassium rocks arose in lagoons into which there was an influx of sea water. Typically, the accumulation of potassium salts occurred in lagoons that communicated with the sea not directly, but through intermediate lagoons in which preliminary precipitation of salts occurred. By this, Yu. V. Morachevsky explains the poverty of Solikamsk potassium deposits in sulfate minerals.
Particularly favorable conditions for the accumulation of salts are created in shallow interconnected lagoons, in which there is a continuous influx of sea water. It is possible that these sea basins were inland and often lost contact with the ocean. In addition, such lagoons were usually located in a zone of rapid subsidence of the earth's crust, on the periphery of a rising mountainous country. This is evidenced by the location of salt deposits in the Western Urals, Carpathian region and a number of other regions (see § 95).
Due to intense evaporation, the concentration of salts in the lagoon increases sharply and at its bottom, under conditions of continuous subsidence, it is possible to accumulate thick salt-bearing strata in the immediate vicinity of the basins, even with very low salinity.
In a number of cases, salt deposits noticeably changed their mineralogical composition during diagenesis under the influence of brines circulating in them. As a result of such diagenetic changes, for example, astrakhanite deposits are formed at the bottom of modern salt lakes in silt deposits.
The intensity of transformation is further enhanced when salt rocks are immersed in zones elevated temperature and a lot of pressure. Therefore, some salt rocks are secondary.
The structure of the salt layers shows that the accumulation of salts was not continuous and alternated with periods of dissolution of previously formed salt layers. It is possible, for example, that due to the dissolution of layers of rock and potassium salts, layers of sulfates appeared, which were a kind of residual formations.
There is no doubt that the formation of salt-bearing strata requires the presence of many favorable conditions. These, in addition to the corresponding physical-geographical and climatic features, include the energetic subsidence of this section of the earth's crust, which causes the rapid burial of salts and protects them from erosion. Uplifts occurring in neighboring areas ensure the formation of closed or semi-closed sea and lagoon basins. Therefore, most of the large salt deposits are located in areas transitioning from platforms to geosynclines extended along folded structures (Solikamskoye, Iletskoye, Bakhmutskoye and other deposits).
Geological distribution. The formation of salt-bearing strata, as well as other sedimentary rocks, occurred periodically. The following eras of salt formation are especially clearly distinguished: Cambrian, Silurian, Devonian, Permian, Triassic and Tertiary.
Cambrian salt deposits are the oldest. They are known in Siberia and Iran, and the Silurian ones are known in North America. The Permian salt-bearing strata are very developed on the territory of the USSR (Soli-Kamsk, Bakhmut, Iletsk, etc.). During the Permian period, the world's largest deposits were formed in Stassfurt, Texas, New Mexico, etc. Large salt deposits are known in the Triassic rocks of North Africa. On the territory of the USSR, there are no salt-bearing strata in Triassic deposits. Salt deposits in Transcarpathia and Subcarpathia, Romania, Poland, Iran and a number of other countries are confined to tertiary deposits. Deposits of gypsum and anhydrite are confined to deposits of the Silurian period in the USA and Canada, Devonian - in the Moscow Basin and the Baltic States, Carboniferous - in the east of the European part of the USSR, Permian - in the Urals, Jurassic - in the Caucasus and Cretaceous - in Central Asia.
Salt formation continues to this day. Already before our eyes, part of the water of the Red Sea evaporated, forming significant accumulations of salts. Numerous salt lakes exist within drainless basins, particularly in Central Asia. .
Halite is the only naturally occurring material classified as a halogen and a subclass of sodium chloride. It is worth adding that halite is the only mineral of its kind that people eat. On in simple language Halite is simple rock or table salt. This name came to us from Ancient Greece (gallos), which translated means salt and sea.
Chemical and physical properties of the mineral
NaCl is chemical formula pure halite, which contains 60.6 chlorine and 39.4% sodium. In its pure form, NaCl can be transparent or translucent, have a characteristic white tint, or have a glassy sheen. The shade of the mineral depends on third-party impurities: when interacting with iron oxide, it produces yellow-red tones, organic components give brown-black colors, and clay impurities color the mineral gray. When interacting with potassium chloride, NaCl turns into a deep blue-lilac color.
This compound appears to us as a fragile material that has hygroscopic properties and a salty taste. It is easily soluble in water and begins the melting process at temperatures above 800 C, turning the fire a rich yellow color. During mining, it is mined in the form of cubic and granular crystals or stalactites.
NaCl products are incredible sensitive to moisture, which leads to their fragility. To preserve products, they should be treated with alcohol, gasoline or various oil bases, and then thoroughly wiped with a velvet material.
Varieties of halite
Due to the influence of various natural factors and conditions, NaCl is divided into the following types:
Origin of the mineral
Large deposits of the mineral began their formation thousands of millions of years ago in the territories North America and Eurasia, just at a time when the named places were characterized by a sultry and dry climate.
Today, rock salt is mined in large quantities in Russia, Ukraine, Germany, Poland and North America.
The healing properties of the mineral
Salt is endowed with a unique anti-inflammatory and antiseptic effect and is indispensable during the treatment of colds and viral ailments.
Halite is a mineral that is used in the preparation of a solution to treat the throat. It contains: water, iodine and salt. It is also used to dull toothache by preparing a solution of warm water and one tablespoon of salt. A bag of hot mineral is excellent for radiculitis, bronchitis, boils and boils. Heated salt is also used to treat a prolonged runny nose.
Magic properties
For many centuries, many peoples were of the opinion that salt is one of the strongest amulets from conspiracies, damage and evil spirits, as well as various troubles and troubles.
In wartime, there was an opinion among soldiers that salt could protect them from death and injury.
Many healers also use modern world salt to attract love, prosperity and health. There is a belief that salt has a powerful connection with the earth and if you carry it with you, a person will strengthen his connection with the earth. Thanks to all this knowledge, incredible things are made many amulets and charms, which consist of salt.
Application
Halite has been used for many thousands of years in various fields and human needs. In the food industry, NaCl is used as a food additive that is used by every person and is common in our kitchen. table salt. Over the course of one year, more than seven million tons of halite are spent on such needs.
In the chemical industries, the mineral is used to produce sodium and chlorine, from which they are subsequently produced baking soda, various high concentration alkaline compounds and hydrochloric acid. It is an integral part of all household detergents, as well as paper products and glass. It is also worth noting that halite film used in the field of optics to create another layer on the lenses.
Halite - a widespread mineral of the halogen class. Synonyms: mountain salt, rock salt, table salt, cracking salt.
Chemical composition
Sodium (Na) 39.4%, chlorine (C1) 60.6%.
Properties
Crystal structure: face-centered cubic lattice: sodium ions (Na +) and chlorine ions (C1 -), alternating in the crystal lattice, are located at the corners of small cubes (see Table 1).
The mineral halite is fragile, hygroscopic, highly soluble in water, and tastes salty. The mineral halite forms cubic crystals, solid granular and dense spar-like masses. In caves and mine workings it forms stalactites, stalagmites, and sinter formations. In lakes and lagoons it forms crystalline growths on various objects - plant branches, stones, etc. Often has a rhythmic-zonal structure.
It is easily soluble in water, has a pleasant salty taste, which differs from the very similar sylvite, which is also easily soluble in water, but has a pungent taste. Halite is of chemogenic origin and is formed as a result of the evaporation of sea water, salt lake waters, and the cooling of salt-saturated solutions.
Minaral halite is also found as a product of volcanic sublimation of high-temperature fumaroles (Etna and Vesuvius, Italy).
It is the main compound dissolved in ocean waters - with a water salinity of 35 ppm, NaCl accounts for about 85%.
Place of Birth
In Russia, huge deposits of the mineral halite of marine origin are known in the Donbass (Artyomovskoye deposit), in the Arkhangelsk region (Solvychegodskoye deposit), in the Orenburg region (Iletsk deposit), in the Verkhnekamsk region of the Perm Territory. Halite deposits of lacustrine origin are known in the Volgograd region (Lake Elton), in Astrakhan region(Lake Baskunchak).
Blue aggregates of the mineral halite are known in Germany, where large deposits of halite are also developed. Beautiful skeletal crystals of the mineral halite are known in the USA.
Application
The mineral halite is an important raw material for the food and chemical industries.
Properties of the mineral
- Origin of name: from Greek words halos - salt and lithos - stone
- Opening year: known since ancient times
- Thermal properties: Melts at 804°C, colors the flame yellow.
- Luminescence: Red (SW UV) .
- IMA status: valid, first described before 1959 (before IMA)
- Typical impurities: I,Br,Fe,O
- Strunz (8th edition): 3/A.02-30
- Hey's CIM Ref.: 8.1.3
- Dana (8th edition): 9.1.1.1
- Molecular Weight: 58.44
- Cell parameters: a = 5.6404(1) Å
- Number of formula units (Z): 4
- Unit cell volume: V 179.44 ų
- Twinning: According to (111) (artificial crystals).
- Space group: Fm3m (F4/m 3 2/m)
- Density (calculated): 2.165
- Density (measured): 2.168
- Pleochroism: weak
- Dispersion of optical axes: moderately strong
- Refractive index: n = 1.5443
- Maximum birefringence:δ = 0.000 - isotropic, does not have birefringence
- Type: isotropic
- Optical relief: short
- Selection form: Cubic crystals, often granular or spar-like masses, stalactites
- USSR taxonomy classes: Chlorides, bromides, iodides
- IMA classes: Halides
- Chemical formula: NaCl
- Syngony: cubic
- Color: Colorless, grey, white, red, yellow, blue, violet
- Trait Color: white
- Shine: glass
- Transparency: transparent translucent translucent
- Cleavage: perfect by (001)
- Kink: conchoidal
- Hardness: 2,5
- Fragility: Yes
- fluorescence: Yes
- taste: Yes
- Literature: Minerals. Directory (edited by F.V. Chukhrov and E.M. Bonstedt-Kupletskaya). T. II, issue. 1. Halides. M.: Nauka, 1963, 296 p.
- Additionally:
Photo of the mineral
Articles on the topic
- Halite or rock salt
Halite forms large crystals that grow in voids and cracks in rocks, less often grown into clay, anhydrite and kainite; huge cubes with a volume of more than 1 cubic meter. m found in the upper reaches of the Aller River (Germany) and near the city of Detroit (USA)
Deposits of the mineral Halite
- Soligorsk, city
- Solikamsk, city
- Chelyabinsk region
- Russia
- Perm region
- Belarus
- Minsk Region
- Berezniki
- California
The chemical formula of halite is NaCl.
halite - rock salt
Halite, or rock salt: this mineral is known to every person, so “ edible mineral» we encounter every day when we eat it. Rock salt, table salt, table salt, table salt are the names of the same natural sodium chloride, widely known since ancient times.
We buy finely crystalline white salt in bags; it is usually iodized. Those who prepare vegetables for the winter purchase coarse, non-iodized salt. It is believed that iodine imparts unnecessary softness to pickled vegetables. This salt has large crystals and a grayish tint.
Few people think about where salt comes from and how it is processed into the product that we are used to seeing in stores. Salt is formed in drying lakes and estuaries, along the shores of shallowing seas. In Kazakhstan, the salt lakes Elton and Baskunchak are widely known, in Turkmenistan the Kara-Bogaz-Gol Bay, which belongs to the Caspian Sea.
At the beginning of the 20th century, salt was extracted by evaporation even from salt lakes in southern Siberia. In Khakassia, this mineral was obtained from the water of salt lakes; saltworks operated until the mid-thirties of the twentieth century. But as a result of climate change, the salinity of the lakes decreased and production was stopped.
Fossil salt layers are also known. This salt was formed by the natural evaporation of ancient bays and shallow seas. The layers can be up to several hundred meters thick and extend over vast distances. Thus, in Canada and the USA, underground salt layers are up to 350 meters thick and stretch from the Appalachians to the Michigan River.
Natural salt sometimes permeates layers of sandstone and other porous rocks. This is how the “salt licks” loved by animals are formed.
Natural salt forms cubic crystals, its color can be white, yellowish, bluish, pink. The taste of salt is salty without bitterness, unlike the taste of sylvite and carnallite, which are often found together with halite. Silvin and carnallit are bitter-salty, sometimes pungently bitter, and eating them by mistake can cause severe indigestion.
Salt is essential for the life of mammals, including humans. Animals come out of the forest “to the salt licks” and lick sedimentary rocks soaked in saline solutions. Lack of salt in food leads to lethargy, weakness, and increased fatigue, especially in hot weather, when salt is excreted through sweat. Lack of salt in the hot season leads to the destruction of bone and muscle tissue, from where the body extracts chlorine and sodium ions to ensure vital functions. Therefore, lack of salt can lead to osteoporosis. Doctors believe that the consequences of a lack of salt can be depression, nervous and mental illness.
At the same time, excess salt in food leads to increased blood pressure, negatively affects all internal organs.
The most ancient saltworks, known to historians, found in excavations in the city of Provadia-Solonitsa in Bulgaria. The city existed six thousand years ago BC. Water from the salt lake was evaporated in large adobe ovens. Judging by the scale of production, salt was produced in large quantities over many centuries, perhaps millennia.
Nowadays, salt (halite) is used not only as a healthy food additive. This is the raw material for the production of chlorine, hydrochloric acid and sodium hydroxide (caustic soda). Salt is sprinkled on city roads in winter to remove ice, and these are not all areas of application of the “edible mineral.”
