Sulfur properties. Sulfur - description and properties of the healing stone Sulfur magical properties

pure yellow sulfur

A mineral from the class of native elements. Sulfur is an example of a well-defined enantiomorphic polymorphism. In nature, it forms 2 polymorphic modifications: rhombic a-sulfur and monoclinic b-sulfur. At atmospheric pressure and a temperature of 95.6 ° C, a-sulfur passes into b-sulfur. Sulfur is vital for the growth of plants and animals, it is part of living organisms and their decomposition products, it is abundant, for example, in eggs, cabbage, horseradish, garlic, mustard, onions, hair, wool, etc. It is also present in coals and oil.

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STRUCTURE

Native sulfur is usually represented by a-sulfur, which crystallizes in a rhombic syngony, rhombo-dipyramidal symmetry. Crystalline sulfur has two modifications; one of them, rhombic, is obtained from a solution of sulfur in carbon disulfide (CS 2) by evaporation of the solvent at room temperature. In this case, diamond-shaped translucent crystals of light yellow color are formed, easily soluble in CS 2 . This modification is stable up to 96°C; at higher temperatures, the monoclinic form is stable. During natural cooling of molten sulfur in cylindrical crucibles, large crystals of rhombic modification with a distorted shape grow (octahedrons, in which corners or faces are partially “cut off”). Such material is called lump sulfur in the industry. Monoclinic modification of sulfur is a long transparent dark yellow needle-shaped crystals, also soluble in CS 2 . When monoclinic sulfur is cooled below 96 ° C, a more stable yellow rhombic sulfur is formed.

PROPERTIES

Native sulfur is yellow, in the presence of impurities - yellow-brown, orange, brown to black; contains inclusions of bitumen, carbonates, sulfates, clay. Crystals of pure sulfur are transparent or translucent, solid masses are translucent at the edges. The luster is resinous to greasy. Hardness 1-2, no cleavage, conchoidal fracture. Density 2.05 -2.08 g / cm 3, fragile. Easily soluble in Canadian balsam, turpentine and kerosene. In HCl and H 2 SO 4 it is insoluble. HNO 3 and aqua regia oxidize sulfur, turning it into H 2 SO 4. Sulfur differs significantly from oxygen in its ability to form stable chains and cycles of atoms.
The most stable are cyclic molecules S 8 having the shape of a crown, forming rhombic and monoclinic sulfur. This is crystalline sulfur - a brittle yellow substance. In addition, molecules with closed (S 4 , S 6 ) chains and open chains are possible. Such a composition has plastic sulfur, a brown substance, which is obtained by sharp cooling of the sulfur melt (plastic sulfur becomes brittle after a few hours, acquires a yellow color and gradually turns into a rhombic one). The formula for sulfur is most often written simply as S, since, although it has a molecular structure, it is a mixture of simple substances with different molecules.
The melting of sulfur is accompanied by a noticeable increase in volume (about 15%). Molten sulfur is a yellow, highly mobile liquid, which above 160 °C turns into a very viscous dark brown mass. The sulfur melt acquires the highest viscosity at a temperature of 190 °C; a further increase in temperature is accompanied by a decrease in viscosity, and above 300 °C the molten sulfur becomes mobile again. This is due to the fact that when sulfur is heated, it gradually polymerizes, increasing the chain length with increasing temperature. When sulfur is heated above 190 °C, the polymer units begin to break down.
Sulfur is the simplest example of an electret. When rubbed, sulfur acquires a strong negative charge.

MORPHOLOGY

It forms truncated-dipyramidal, rarely dipyramidal, pinacoidal or thick-prismatic crystals, as well as dense cryptocrystalline, confluent, granular, less often fine-fibred aggregates. The main forms on the crystals: dipyramids (111) and (113), prisms (011) and (101), pinacoid (001). Also intergrowths and druses of crystals, skeletal crystals, pseudostalactites, powdery and earthy masses, raids and smears. Crystals are characterized by multiple parallel intergrowths.

ORIGIN

Sulfur is formed during volcanic eruptions, during the weathering of sulfides, during the decomposition of gypsum-bearing sedimentary strata, and also in connection with the activity of bacteria. The main types of native sulfur deposits are volcanogenic and exogenous (chemogenic-sedimentary). Exogenous deposits predominate; they are associated with gypsum anhydrites, which, under the influence of hydrocarbon and hydrogen sulfide emissions, are reduced and replaced by sulfur-calcite ores. All the largest deposits have this infiltration-metasomatic genesis. Native sulfur is often formed (except for large accumulations) as a result of the oxidation of H 2 S. The geochemical processes of its formation are significantly activated by microorganisms (sulfate-reducing and thionic bacteria). Associated minerals are calcite, aragonite, gypsum, anhydrite, celestite, and sometimes bitumen. Among volcanic deposits of native sulfur, hydrothermal-metasomatic (for example, in Japan), formed by sulfur-bearing quartzites and opalites, and volcanogenic-sedimentary sulfur-bearing silts of crater lakes are of primary importance. It is also formed during fumarole activity. Being formed under the conditions of the earth's surface, native sulfur is still not very stable and, gradually oxidizing, gives rise to sulfates, Ch. like plaster.
Used in the production of sulfuric acid (about 50% of the extracted amount). In 1890, Hermann Frasch suggested melting sulfur underground and extracting it to the surface through wells, and at present sulfur deposits are being developed mainly by smelting native sulfur from underground layers directly in places of its occurrence. Sulfur is also large quantities contained in natural gas (in the form of hydrogen sulfide and sulfur dioxide), during gas production it is deposited on the walls of pipes, putting them out of action, so it is captured from the gas as soon as possible after production.

APPLICATION

Approximately half of the sulfur produced is used in the production of sulfuric acid. Sulfur is used to vulcanize rubber, as a fungicide in agriculture and as colloidal sulfur - a drug. Also, sulfur in the composition of sulfur-bitumen compositions is used to obtain sulfur asphalt, and as a substitute for Portland cement - to obtain sulfur concrete. Sulfur is used in the production of pyrotechnic compositions, was previously used in the production of gunpowder, and is used in the production of matches.

Sulfur - S

CLASSIFICATION

Chalcogens are a group of elements to which sulfur belongs. Its chemical symbol is S, the first letter of the Latin name Sulfur. The composition of a simple substance is written using this symbol without an index. Consider the main points regarding the structure, properties, production and use of this element. The characterization of sulfur will be presented in as much detail as possible.

Common features and differences of chalcogens

Sulfur belongs to the oxygen subgroup. This is the 16th group in the modern long period image form. periodic system(PS). An obsolete version of the number and index is VIA. Titles chemical elements groups, chemical signs:

• oxygen (O);
• sulfur (S);
• selenium (Se);
• tellurium (Te);
• polonium (Po).

The outer electron shell of the above elements has the same structure. In total it contains 6 who can participate in education chemical bond with other atoms. Hydrogen compounds correspond to the composition H 2 R, for example, H 2 S is hydrogen sulfide. The names of the chemical elements that form two types of compounds with oxygen: sulfur, selenium and tellurium. General formulas oxides of these elements - RO 2, RO 3.

Chalcogens correspond to simple substances that differ significantly in physical properties. The most common chalcogens in the earth's crust are oxygen and sulfur. The first element forms two gases, the second - solids. Polonium, a radioactive element, is rarely found in the earth's crust. In the group from oxygen to polonium, non-metallic properties decrease and metallic properties increase. For example, sulfur is a typical non-metal, while tellurium has a metallic luster and electrical conductivity.

Element No. 16 of the D.I. Mendeleev

The relative atomic mass of sulfur is 32.064. Of the natural isotopes, 32 S is the most common (more than 95% by weight). Nuclides with atomic masses of 33, 34 and 36 are found in smaller quantities. Characteristics of sulfur by position in PS and atomic structure:

• serial number - 16;
• the charge of the nucleus of an atom is +16;
• atomic radius - 0.104 nm;
• ionization energy -10.36 eV;
• relative electronegativity - 2.6;
• oxidation state in compounds - +6, +4, +2, -2;
• valency - II (-), II (+), IV (+), VI (+).

Sulfur is in the third period; electrons in an atom are located on three energy levels: on the first - 2, on the second - 8, on the third - 6. All external electrons are valence. When interacting with more electronegative elements, sulfur gives up 4 or 6 electrons, acquiring typical oxidation states of +6, +4. In reactions with hydrogen and metals, the atom attracts the missing 2 electrons until the octet is filled and a steady state is reached. in this case it drops to -2.

Physical properties of rhombic and monoclinic allotropic forms

Under normal conditions, sulfur atoms are connected to each other at an angle into stable chains. They can be closed in rings, which allows us to speak about the existence of cyclic sulfur molecules. Their composition reflect the formulas S 6 and S 8 .

The characterization of sulfur should be supplemented by a description of the differences between allotropic modifications with different physical properties.

Rhombic or α-sulfur is the most stable crystalline form. These are bright yellow crystals composed of S 8 molecules. The density of rhombic sulfur is 2.07 g/cm3. Light yellow monoclinic crystals are formed by β-sulfur with a density of 1.96 g/cm3. The boiling point reaches 444.5°C.

Obtaining amorphous sulfur

What color is sulfur in the plastic state? It is a dark brown mass, completely different from yellow powder or crystals. To obtain it, you need to melt rhombic or monoclinic sulfur. At temperatures above 110°C, a liquid is formed, with further heating it darkens, at 200°C it becomes thick and viscous. If you quickly pour molten sulfur into cold water, then it will solidify with the formation of zigzag chains, the composition of which is reflected by the formula S n.

Solubility of sulfur

Some modifications in carbon disulfide, benzene, toluene and liquid ammonia. If organic solutions are cooled slowly, needle-like crystals of monoclinic sulfur are formed. When liquids evaporate, transparent lemon-yellow crystals of rhombic sulfur are released. They are brittle and can be easily ground into powder. Sulfur does not dissolve in water. The crystals sink to the bottom of the vessel, and the powder can float on the surface (not wetted).

Chemical properties

The reactions show the typical non-metallic properties of element No. 16:

• sulfur oxidizes metals and hydrogen, is reduced to the S 2- ion;
• when burned in air and oxygen, di- and sulfur trioxide are formed, which are acid anhydrides;
• in a reaction with another more electronegative element - fluorine - sulfur also loses its electrons (is oxidized).

Free sulfur in nature

In terms of prevalence in the earth's crust, sulfur is in 15th place among the chemical elements. The average content of S atoms in is 0.05% by weight earth's crust.

What color is sulfur in nature (native)? It is a light yellow powder with a characteristic odor or yellow crystals with a glassy luster. Deposits in the form of placers, crystalline layers of sulfur are found in areas of ancient and modern volcanism: in Italy, Poland, Central Asia, Japan, Mexico, and the USA. Often, when mining, beautiful druze and giant single crystals are found.

Hydrogen sulfide and oxides in nature

In areas of volcanism, gaseous sulfur compounds come to the surface. The Black Sea at a depth of over 200 m is lifeless due to the release of hydrogen sulfide H 2 S. The formula of sulfur oxide is bivalent - SO 2, trivalent - SO 3. The listed gaseous compounds are present in some oil, gas, and natural water fields. Sulfur is part of coal. It is necessary for the construction of many organic compounds. When egg whites rot, hydrogen sulfide is released, which is why it is often said that this gas has the smell of rotten eggs. Sulfur is a biogenic element, it is necessary for the growth and development of humans, animals and plants.

Importance of natural sulfides and sulfates

The characterization of sulfur will be incomplete, if not to say that the element occurs not only in the form of a simple substance and oxides. The most common natural compounds are salts of hydrosulfide and sulfuric acids. Sulfides of copper, iron, zinc, mercury, lead are found in the minerals sphalerite, cinnabar and galena. Sulfates include sodium, calcium, barium and magnesium salts, which form minerals and rocks in nature (mirabilite, gypsum, selenite, barite, kieserite, epsomite). All these compounds are used in various sectors of the economy, used as raw materials for industrial processing, fertilizers, building materials. Veliko medical significance some crystalline hydrates.

Receipt

A yellow substance in a free state occurs in nature at different depths. If necessary, sulfur is smelted from rocks, not by raising them to the surface, but by forcing superheated rocks to a depth. Another method is associated with sublimation from crushed rocks in special furnaces. Other methods involve dissolution with carbon disulfide or flotation.

The needs of industry for sulfur are great, therefore, its compounds are used to obtain elemental matter. In hydrogen sulfide and sulfides, sulfur is in reduced form. The oxidation state of the element is -2. Sulfur is oxidized, increasing this value to 0. For example, according to the Leblanc method, sodium sulfate is reduced with coal to sulfide. Then calcium sulfide is obtained from it, treated with carbon dioxide and water vapor. The resulting hydrogen sulfide is oxidized with atmospheric oxygen in the presence of a catalyst: 2H 2 S + O 2 = 2H 2 O + 2S. The determination of sulfur obtained by various methods sometimes gives low purity values. Refining or purification is carried out by distillation, rectification, treatment with mixtures of acids.

The use of sulfur in modern industry

Sulfur granulated is used for various production needs:

1. Obtaining sulfuric acid in the chemical industry.
2. Production of sulfites and sulfates.
3. Production of preparations for plant nutrition, control of diseases and pests of agricultural crops.
4. Sulfur-containing ores are processed at mining and chemical plants to obtain non-ferrous metals. Accompanying production is sulfuric acid.
5. Introduction to the composition of some grades of steels to impart special properties.
6. Thanks get rubber.
7. Manufacture of matches, pyrotechnics, explosives.
8. Use for the preparation of paints, pigments, artificial fibers.
9. Bleaching fabrics.

Toxicity of sulfur and its compounds

Dust-like particles with an unpleasant odor irritate the mucous membranes of the nasal cavity and respiratory tract, eyes, skin. But the toxicity of elemental sulfur is not considered particularly high. Inhalation of hydrogen sulfide and dioxide can cause severe poisoning.

If, during the roasting of sulfur-containing ores at metallurgical plants, exhaust gases are not captured, then they enter the atmosphere. Combining with drops and water vapor, sulfur and nitrogen oxides give rise to the so-called acid rain.

Sulfur and its compounds in agriculture

Plants absorb sulfate ions along with the soil solution. A decrease in sulfur content leads to a slowdown in the metabolism of amino acids and proteins in green cells. Therefore, sulfates are used for fertilizing crops.

To disinfect poultry houses, basements, vegetable stores, a simple substance is burned or the premises are treated with modern sulfur-containing preparations. Sulfur oxide has antimicrobial properties, which has long been used in the production of wines, in the storage of vegetables and fruits. Sulfur preparations are used as pesticides to control diseases and pests of crops (powdery mildew and spider mites).

Application in medicine

The great healers of antiquity Avicenna and Paracelsus attached great importance to the study of the medicinal properties of yellow powder. Later it was found that a person who does not receive enough sulfur with food becomes weaker, experiences health problems (these include itching and flaking of the skin, weakening of hair and nails). The fact is that without sulfur, the synthesis of amino acids, keratin, and biochemical processes in the body is disrupted.

Medical sulfur is included in ointments for the treatment of skin diseases: acne, eczema, psoriasis, allergies, seborrhea. Sulfur baths can relieve the pain of rheumatism and gout. For better absorption by the body, water-soluble sulfur-containing preparations have been created. This is not a yellow powder, but a white crystalline substance. When used externally, this compound is incorporated into a skin care cosmetic.

Gypsum has long been used in the immobilization of injured parts of the human body. prescribed as a laxative. Magnesia lowers blood pressure, which is used in the treatment of hypertension.

Sulfur in history

Even in ancient times, a non-metallic yellow substance attracted the attention of a person. But it wasn't until 1789 that the great chemist Lavoisier established that powders and crystals found in nature were composed of sulfur atoms. It was believed that the unpleasant smell that occurs when it is burned, repels all evil spirits. The formula for sulfur oxide, which is obtained during combustion, is SO 2 (dioxide). It is a toxic gas and is hazardous to health if inhaled. Several cases of mass extinction of people by entire villages on the coasts, in the lowlands, scientists explain the release of hydrogen sulfide or sulfur dioxide from the earth or water.

The invention of black powder increased military interest in yellow crystals. Many battles were won thanks to the ability of craftsmen to combine sulfur with other substances in the manufacturing process. The most important compound - sulfuric acid - also learned to use a very long time ago. In the Middle Ages, this substance was called vitriol oil, and salts were called vitriol. blue vitriol CuSO 4 and ferrous sulfate FeSO 4 still have not lost their importance in industry and agriculture.

For a person - a "mineral of beauty".

In animals and humans sulfur performs irreplaceable functions: it provides the spatial organization of protein molecules necessary for their functioning, protects cells, tissues and pathways of biochemical synthesis from oxidation, and the entire body from the toxic effects of foreign substances.

The daily requirement of the human body- 0.5-3 g (according to other sources - 4-5 g).

Sulfur enters the body with food, as part of inorganic and organic compounds. Most of the sulfur enters the body in the composition of amino acids.
inorganic compounds sulfur (salts of sulfuric and sulfurous acids) are not absorbed and are excreted from the body with feces. Organic protein compounds are cleaved and absorbed in the intestine.

The sulfur content in the body of an adult is about 0.16% (110 g per 70 kg of body weight). Sulfur is found in all tissues of the human body, especially a lot of it in the muscles, skeleton, liver, nervous tissue, blood. The superficial layers of the skin are also rich in sulfur, where sulfur is part of keratin and melanin.
Sulfur is found in tissues in a wide variety of forms - both inorganic (sulfates, sulfites, sulfides, thiocyanates, etc.) and organic (thiols, thioethers, sulfonic acids, thiourea, etc.). In the form of sulfate anion, sulfur is present in body fluids. The sulfur atoms are integral part molecules of essential amino acids (cystine, cysteine, methionine), hormones (insulin, calcitonin), vitamins (biotin, thiamine), glutathione, taurine and other compounds important for the body. In their composition, sulfur is involved in redox reactions, tissue respiration, energy production, transfer of genetic information, and performs many other important functions.
Sulfur is a component of the structural protein of collagen. Chondroitin sulfate is present in the skin, cartilage, nails, ligaments and myocardial valves. Important sulfur-containing metabolites are also hemoglobin, heparin, cytochromes, fibrinogen and sulfolipids.

Sulfur is excreted mainly in the urine as neutral sulfur and inorganic sulfates, a smaller part of sulfur is excreted through the skin and lungs, and is excreted mainly in the urine as SO 4 2–.
Endogenous sulfuric acid, formed in the body, takes part in the neutralization of toxic compounds (phenol, indole, etc.), which are produced by the intestinal microflora, and also binds substances foreign to the body, including medications and their metabolites. In this case, harmless compounds are formed - conjugates, which are then excreted from the body.
Sulfur metabolism is controlled by those factors that also have a regulatory effect on protein metabolism (hormones of the pituitary, thyroid, adrenal, gonads).

Biological role in the human body. In the human body, sulfur is an indispensable component of cells, enzymes, hormones, in particular insulin, which is produced by the pancreas, and sulfur-containing amino acids (methionine, cysteine, taurine and glutathione).
Sulfur is a part of biologically active substances (histamine, biotin, lipoic acid, etc.). The composition of the active centers of the molecules of a number of enzymes includes SH-groups that take part in many enzymatic reactions, in particular, in the creation and stabilization of the native three-dimensional structure of proteins, and in some cases act directly as catalytic centers of enzymes, they are part of various coenzymes, including coenzyme A.
Sulfur is part of hemoglobin, found in all tissues of the body, is necessary for the synthesis of collagen - a protein that determines the structure of the skin.
In the cell, sulfur provides such a delicate and complex process as energy transfer: it transfers electrons by accepting one of the unpaired oxygen electrons into a free orbital. Sulfur is involved in the fixation and transport of methyl groups.

Sulfur disinfects the blood increases the body's resistance to bacteria and protects the protoplasm of cells, promotes the implementation of oxidative reactions necessary for the body, enhances the secretion of bile, protects against the harmful effects of toxic substances, protects the body from the harmful effects of radiation and pollution environment, thereby slowing down the aging process. This explains the high need of the body for this element.

Signs of sulfur deficiency: constipation, allergies, dullness and hair loss, brittle nails, high blood pressure, joint pain, tachycardia, high level sugar and high blood triglycerides.

In advanced cases - fatty degeneration of the liver, hemorrhages in the kidneys, disorders of protein and carbohydrate metabolism, overexcitation nervous system, irritability.
Sulfur deficiency in the body does not happen often, since most foods contain enough of it.

In recent decades, one of the sources excess intake of sulfur in the human body steel sulfur-containing compounds ( sulfites ), which are added to many foods, alcoholic and non-alcoholic beverages as preservatives . Especially a lot of sulfites in smoked meats, potatoes, fresh vegetables, beer, cider, ready-made salads, vinegar, wine dyes. It is possible that sulfite consumption, which is constantly increasing, is partly to blame for the increase in the incidence bronchial asthma . It is known, for example, that 10% of patients with bronchial asthma exhibit hypersensitivity to sulfites (i.e. sensitized to them). To reduce negative impact sulfites on the body, it is recommended to increase the content in the diet of cheeses, eggs, fatty meat, poultry meat.

The main manifestations of excess sulfur in the body: itching, rash, furunculosis, redness and swelling of the conjunctiva; the appearance of small point defects on the cornea; aches in the eyebrows and eyeballs, a feeling of sand in the eyes; photophobia, lacrimation, general weakness, headaches, dizziness, nausea, catarrh of the upper respiratory tract, bronchitis; hearing loss, indigestion, diarrhea, weight loss; anemia, mental disorders, decreased intelligence.

Food sources of sulfur: vegetables:

Sulfur (mineral) - often found in native form, forming dense or earthy masses or crystalline aggregates in the form of crystalline drusen, films and deposits. There are also well-formed crystals reaching considerable sizes. Crystals of native S. belong to the rhombic system (rhombic bipyramid class) and have a pyramidal habit, see fig. No. 1 and 2. Sometimes, due to the uneven development of the planes of the bipyramid, a sphenoid form of crystals is obtained. The most common forms found on S. crystals: the main rhombic bipyramid (111) P, the axes of which are related A:b:With= 0.8138:1:1.9076; in addition: (113)S; (011)n and (001)s. Crystals sometimes coalesce with each other in a twin position. When split, it reveals a characteristic conchoidal fracture. S.'s hardness is insignificant, 1.5-2.5 (on the Mohs scale). Specific gravity 1.9-2.1. The color of native S. is different (from impurities of selenium, arsenic sulfide, organic substances): honey-yellow, sulfur-yellow, gray and brown. Luster is greasy, approaching diamond. S. is distinguished by strong birefringence, which in the case of a transparent crystal can be observed (as in Icelandic spar) directly, without any instruments. optically negative. The plane of the optical axes lies in the brachydiagonal section. optical angle axles 2 r= 69° 40′. For other properties of S. - see the chemical part of the article. Native S. is formed in nature in various ways. Largest Quantities occur by water from sources and in general waters circulating in the bowels of the earth's crust containing hydrogen sulfide. The latter, when exposed to atmospheric oxygen, is oxidized, forming water and releasing C. Similar sources are formed where there are deposits of gypsum and organic matter. Due to a number of chemical transformations from gypsum, under the action of organic substances and water, hydrogen sulfide is formed, and from the latter - S. The co-occurrence of gypsum, calcareous spar, sulfur sources, S. and organic substances is explained by a similar origin. Sometimes native S. closely adjoins and even takes root in large gypsum crystals. S. for the most part is in the form of veins, nests, zhevlaks in clays, marls and gypsum. These are the most famous deposits of Sicily, Aragon, Croatia, Dagestan, Poland and the Kazan province. The second method of S.'s formation is volcanic. It is deposited along the walls of the crater of volcanoes either as a result of direct sublimation, or as a result of the interaction of hydrogen sulfide and sulfur dioxide, the presence of which is very common in the products of volcanic activity. S.'s allocation is explained by the equation: 2H 2 S + SO 2 \u003d 2H 2 O + 3S. Finally, apparently, sulfur is also formed in nature in a third way: sulfur compounds of metals during oxidation can release free sulfur. This can explain the joint presence of the latter, for example, with sulfur pyrite (Soymonovskoye deposit in the Urals, Rio Tinto in Spain) . On the amount of S. produced annually and its application -

Sulfur (from lat. serum"Whey") - a mineral of the class of native elements, non-metal. The Latin name is associated with Indo-European root swelp - "burn". Chemical formula: S.

Sulfur, unlike other native elements, has a molecular lattice, which determines its low hardness (1.5-2.5), lack of cleavage, brittleness, uneven fracture and the resulting greasy splash; only on the surface of the crystals is a glassy luster observed. Specific gravity 2.07 g/cm 3 . It has poor electrical conductivity, poor thermal conductivity, low melting point (112.8°C) and ignition (248°C). Lights up easily from a match and burns with a blue flame; in this case, sulfur dioxide is formed, which has a sharp suffocating odor. The color of native sulfur is light yellow, straw yellow, honey yellow, greenish; sulfur containing organic substances acquire a brown, gray, black color. Volcanic sulfur is bright yellow, orange, greenish. Usually yellowish in places. There is a mineral in the form of continuous dense, sinter, earthy, powdery masses; there are also overgrown crystals, nodules, raids, crusts, inclusions and pseudomorphs on organic residues. The syngony is rhombic.

Features : Native sulfur is characterized by: non-metallic luster and the fact that it catches fire from a match and burns, releasing sulfur dioxide, which has a sharp suffocating odor. The most characteristic color for native sulfur is light yellow.

Variety:

Volcanite(selenium sulfur). Orange-red, red-brown. The origin is volcanic.

Monoclinic sulfur Crystalline sulfur Crystalline sulfur Selenium sulfur - volcanite

Chemical properties of sulfur

It lights up from a match and burns with a blue flame, while sulfur dioxide is formed, which has a sharp suffocating smell. Easily melts (melting point 112.8 ° C). Ignition temperature 248°C. Sulfur dissolves in carbon disulfide.

Origin of sulfur

There is native sulfur of natural and volcanic origin. Sulfur bacteria live in water basins enriched with hydrogen sulfide due to the decomposition of organic residues - at the bottom of swamps, estuaries, shallow sea bays. The estuaries of the Black Sea and the Sivash Bay are examples of such water bodies. The concentration of sulfur of volcanic origin is confined to the vents of volcanoes and to the voids of volcanic rocks. During volcanic eruptions, various sulfur compounds (H 2 S, SO 2) are released, which are oxidized under surface conditions, which leads to its reduction; in addition, sulfur sublimes directly from the vapor.

Sometimes during volcanic processes, sulfur is poured out in liquid form. This happens when sulfur, which has previously settled on the walls of craters, melts with increasing temperature. Sulfur is also deposited from hot aqueous solutions as a result of the decay of hydrogen sulfide and sulfur compounds released in one of the late phases of volcanic activity. These phenomena are now observed near the vents of the geysers of Yellowstone Park (USA) and Iceland. It occurs together with gypsum, anhydrite, limestone, dolomite, rock and potassium salts, clays, bituminous deposits (oil, ozocerite, asphalt) and pyrite. It is also found on the walls of volcano craters, in cracks in lavas and tuffs surrounding the vents of both active and extinct volcanoes, near sulfur mineral springs.

satellites. Among the sedimentary rocks: gypsum, anhydrite, calcite, dolomite, siderite, rock salt, sylvin, carnallite, opal, chalcedony, bitumen (asphalt, oil, ozocerite). In deposits formed as a result of the oxidation of sulfides - mainly pyrite. Among the products of volcanic sublimation: gypsum, realgar, orpiment.

Application

Widely used in the chemical industry. Three-quarters of the sulfur produced is used to make sulfuric acid. It is also used to combat agricultural pests, in addition, in the paper, rubber industry (rubber vulcanization), in the production of gunpowder, matches, in pharmaceuticals, glass, Food Industry.

Sulfur deposits

On the territory of Eurasia, all industrial deposits of native sulfur are of surface origin. Some of them are located in Turkmenistan, in the Volga region, etc. Rocks containing sulfur stretch along the left bank of the Volga from the city of Samara in a strip several kilometers wide to Kazan. Probably, sulfur was formed in the lagoons during the Permian period as a result of biochemical processes. Sulfur deposits are located in Razdol (Lviv region, Prykarpattya), Yavorovsk (Ukraine) and in the Ural-Emba region. In the Urals (Chelyabinsk region), sulfur is found, formed as a result of the oxidation of pyrite. Sulfur of volcanic origin is found in Kamchatka and Kuril Islands. The main reserves are in Iraq, the USA (Louisiana and Utah), Mexico, Chile, Japan and Italy (Sicily).