Properties of the mineral galena. Big encyclopedia of oil and gas

Properties

Syngony: Cubic

Composition (formula): PbS

Color:

Tin gray, lead gray, pinkish lead gray

Dash color (powder color): grayish black

Transparency: Opaque

Cleavage: Perfect

Fracture: Conchoidal

Luster: Metallic

Hardness: 2-3

Specific gravity, g / cm 3: 7,2-7,6

Special properties:

The mineral dissolves in nitric acid

Selection form

The mineral galena occurs in the form of cubic, cubo-octahedral, less often lamellar, columnar and skeletal crystals. Also, galena forms twins of intergrowth and germination, continuous coarse and fine-grained masses, loose, farinaceous segregations of a grape-like form.

Origin

The mineral galena is widely distributed in hydrothermal and metasomatic deposits. This mineral is one of the most common hydrothermal sulfides. Known deposits of skarn-type galena. In the form of separate grains, the mineral galena is found in acidic and alkaline rocks, and in pegmatites. Sometimes galena can be found in veins, veins and voids in limestones.
There are pseudomorphs of galena after bornite, fahlore, anglesite, cerussite, chalcocite and pyromorphite.

Deposits / manifestations

Beautiful crystals of the mineral galena are found in Dalnegorsk (Primorye, Russia), at the Zavodinskoye deposit (Rudny Altai), in Australia (Broken Hill), USA (Joplin, Missouri; Galena, Kansas; Picher, Oklahoma; Sweetwater mine, Missouri), in Mexico (Chihuahua) and Germany (Neudorf).
Octahedral crystals of the mineral galena are often found in Pribram (Czech Republic). Cubic crystals of galena are mined in Madan (Bulgaria). Twins of galena according to the spinel law are known in Herzhe (Romania).

Application

The mineral galena is the main ore for lead. Sometimes silver, bismuth and selenium are extracted from galena along the way.

The mineral galena is one of the salts of hydrosulphuric acid, called sulfides. In association with sphalerite, it belongs to the class of so-called polymetallic ores. Refers to toxic minerals that pose a potential hazard.

Origin and deposits

Galena stone is the main lead ore of hydrothermal (more often low and medium temperature) or metasomatic origin. It can be found in limestone veins and voids, among acidic and alkaline minerals, and also near pegmatites. Most often it is found in places of deposits:

• zinc blende (sphalerite),
• sulfur pyrite (pyrite),
• copper pyrite (chalcopyrite),
• rock-forming mineral of igneous and metamorphic rocks - quartz,
• fluorspar (fluorite),
• salts of carbonic acid - carbonates.

Translated from Latin, galena means "lead ore. Therefore, galena is often called a poisonous stone.

In the process of weathering, it forms lead, the white lead ore cerussite and anhydrous lead sulfate anglesite. Under the influence of heat and groundwater, together with oxygen, it becomes covered with brown deposits or crusts. gray color. Galena is often confused with arsenic pyrite - arsenopyrite, but differs from it in color, more low scores hardness and high density.

Place of Birth

Among sulfides of hydrothermal origin, galena rock is one of the most widespread. Known deposits of galena stone are of the skarn type. Among the world leaders mining it:

• Russia - Altai and East Siberian deposits, Sadonskoye vein of the North Caucasus, Nerchinskoye in the territory of Transbaikalia, Dalnegorsk ore field located in Primorye,
• America - in the states of Oklahoma, Kansas and Missouri,
• Australia - Broken Hill,
• Central Asia - Karamazar mountains,
• Mexico - Chihuahua and Eulalia,
• Romania - Herce,
• Bulgaria - Madan,
• Italy - Ribble in the Carnic Mountains and Mountain Dossena in Lombardy, Monteponi in Sardinia.

Galena deposits are also found in North Africa in Morocco and in South Africa in Namibia. The most ancient mines of galena rock in a practically exhausted state are still preserved in the central and northern parts of Europe, including Germany (Neudorf and Freiberg) and the Czech Republic (Pribram).

Chemical composition

Interesting composition

The chemical formula of galena includes inorganic compounds:

• 86.6% lead,
• 13.4% sulfur.

According to its characteristics, it is lead sulfide. Quite often, impurities are present in the chemical composition of galena, including silver, cadmium, bismuth, selenium, copper, zinc, arsenic, antimony. Because of a large number included in chemical composition lead component specimens of the mineral rock have a large mass, and the stone is heavy.

The mineral dissolves under the influence of nitric acid.

Structure

By its structure, galena is cubic. It is formed from cubic, cuboctahedral and sometimes octahedral crystals with conchoidal fracture. A fracture that is uneven in terms of characteristics is obtained quite rarely for galena stones.

In some cases, it can be formed by lamellar, columnar or skeletal crystals. It is capable of forming intergrowths and intergrowths with continuous fine- and coarse-grained masses, as well as with inclusions of loose and farinaceous exudates mixed with sphalerite, called cockade ore.

Mineral properties

The hardness of the mineral on the Mohs scale: 2.5-3.0. Density from 7.2 to 7.6 grams per cubic cm. The mineral is quite fragile and breaks under mechanical impact.

Among the properties of galena, its good electrical conductivity is noted.

Optical properties

In galena, the main color is lead. Also found in nature:

• pink lead,
• lead grey,
• green,
• yellow,
• brown,
• white and
• bluish hues.

The mineral rock has a metallic luster. The stone is completely opaque. The mineral galena quickly loses its silvery luster in the process of oxidation upon contact with air, under the influence of direct sun rays and when exposed to moisture. As a result, devoid of luster, it becomes dark.

magical properties

The mineral is credited with a number of magical properties:

• give him the ability to transform negative energy into positive emotions
• used as talismans by those who strive for fame,
• advise in the form of an amulet for people who require constant introspection and philosophical thinking.

Medicinal properties

Medicinal properties of galena:

• to lift vitality and harmonization of the general psycho-emotional state,
• to normalize sleep and get rid of depressive and apathetic conditions,
• to strengthen blood vessels and removal of inflammatory processes,
• in the fight against bad mood and to increase activity,
• against alcohol, tobacco and drug addiction,
• for a positive impact on metabolic processes and decrease in appetite if you want to lose weight.

Applications

The scope of galena is limited mainly to the metallurgical industry and chemical production.

Metallurgy

Galena rock acts mainly as an ore for the purpose of obtaining lead from it, however, in some cases, simultaneously with lead, silver, selenium, zinc, or bismuth can also be extracted from it as by-products.

English name - Galenite

origin of name

The Latin name for the mineral galena - lead ore is mentioned by Pliny. The name galena was given by Kobel (1838).

Synonyms for the mineral galena:

Galena(Glocker, 1847). Apparently, mixtures of galena with other minerals are steinmannite (Ziepe, 1833), thargionite (Bahey, 1852), cuproplumbite (Breithaupt, 1844), johnstonite (Heidinger, 1845), alysonite (Field, 1859), furietite (Maine, 1860). ), guascolite (Dana, 1868), plumbocuprite and nolascite (Adam, 1869), paracobellite (Schrauf, 1871), kilmacuite (Tishborn, 1885).
Under the name Svinchak, fine-grained masses of galena are combined with matt gloss. Quirogite from the Sierra Almagrera (Spain), described by Navaro (1895) as a tetragonal mineral, turned out to be galena of a special, distorted appearance according to X-ray data. A mixture of galena with Zn and Ag sulfides turned out to be castillite (Ramelsberg, 1866; Kalb, 1923). Richmondite (Skay, 1877) - a mixture of galena, fahlore, sphalerite and others. Plumbomangite (Kökhlin, 1911) is a mixture of galena with various ore minerals.

An intergrowth of crystals with forms of uneven development on the faces and edges of the cube. Primorye Dalnegorskoye field

Chemical composition of galena

Theoretical chemical composition of the mineral: Pb - 86.60; S - 13.40. S is isomorphically replaced by Se; there is a continuous isomorphic series of galena (PbS) - claustalite (PbSe), various representatives of which are found in nature. often contains an admixture of Ag, usually up to 0.1%, rarely 0.5-1% or more, which is partly due to the presence of inclusions of silver sulfides, partly due to the presence of AgBiS 2 in solid solution. Analyzes also show the presence of Zn, Cd, Sb, Bi, Cu, Sn, In, Tl, Au, Pt and others (usually not more than tenths of a percent); in most cases, this is due to the presence of impurities of other minerals: sphalerite, boulangerite, chalcopyrite and others.
Lead in galena is a mixture of Pb 204 , Pb 206 , Pb 207 , and Pb 208 isotopes. The last three isotopes in the earth's crust are continuously accumulated due to the radioactive decay of U and Th. The lead isotopic composition of galena can be used to determine the absolute age.

Varieties

Selenite galena of Rudny Altai, containing a small amount of Se, and intermediate members of the galena-clausthalite series from Colorado (USA), in which the PbSe content varies from 6.5 to 93.7 mol. %. Altai selenium galena has a density of 7.2 - 7.5. Cleavage planes have a dull luster, tarnishing is not uncommon - from bronze-yellow to bluish-black. Unlike ordinary galena, it is less resistant to weathering. Occurs in the Zyryanovsky and Chudak deposits as veinlets among copper ores in association with chalcopyrite, pyrite, and tetrahedrite. Galena-claustalites of the Colorado Plateau (USA) form inclusions in sulfide veinlets of uranium-vanadium deposits.

Svinchak - dense matte galena.

Crystallographic characteristic

Syngony cubic, hexaoctahedral class

Crystal structure Face-centered cubic lattice with four molecules per unit cell.

Main shapes: cubic, cuboctahedral, octahedral, rarely trioctahedral and hexoctahedral. Skeletal crystals of a cubic appearance are known. Unevenly developed crystals are not uncommon, elongated, columnar, elongated, and also tabular along the face of a cube or octahedron.

Form of being in nature

Shape of crystals.

Crystals - from small to large (several centimeters in size) - are rarely ingrown, in most cases they grow and form drusen and groups.

The twins of the mineral according to (111) are frequent, the twins of intergrowth and intergrowth are most common, often tabular, sometimes polysynthetic; twin intergrowths along (441), along (311) and (331) are observed, causing oblique streaks on the faces of the cube; twin intergrowths after (520) or (730) are indicated in galena from Ratiborzhitsa (Czech Republic), secondary deformation twins after (322), (221), (771) and (411). Forms oriented intergrowths with cotunnite, phosgenite and anglesite, pyrite, chalcopyrite, bournonite, fahlore, pyrrhotite, arsenopyrite, pyromorphite.

Aggregates.

The most common are grains and granular aggregates, less often - dense masses of druses, sometimes - sinter aggregates; crystals and crystalline skeletal formations are relatively common.

Physical Properties
Optical

• The color is lead-gray, somewhat lighter in fine-grained aggregates; galena with octahedral separation containing Bi is somewhat darker; sometimes there is a variegated discoloration.
• The line is greyish-black.
• Shine metallic, strong on cleavage planes; galena with octahedral separation has a slightly duller luster; dense differences are often dull.

Perfect cleavage in three directions

Mechanical

• Hardness 2-3.
• Density 7.4-7.6
• The cleavage is perfect (according to the cube), in three directions parallel to the faces of the cube (100).

Separation along (111) is sometimes observed, which is characteristic of galena with a high content of bismuth, which is explained by bismuthine inclusions located partly along (111) of galena (the result of the decomposition of a solid solution of bismuth sulfide in galena) or the existence of a solid solution of AgBiS 2 in galena. When heated, the octahedral separation disappears and is replaced by cube cleavage.

The fracture of the mineral in dense masses is flat-conchoidal, uneven; in galena with octahedral separation, the fracture is finely stepped.

Galena. Chemical properties

The mineral dissolves in HNO 3 with the release of S and lead sulfate; from a nitric acid solution, when HCl is added, a white precipitate of PbCl 2 precipitates, soluble in hot water. Galena also decomposes with hot or strong HCl.
Solutions of NaCl, CaCl 2 have an effect on the mineral, especially at elevated temperature and pressure.
In polished sections, it quickly turns black from HNO 3, slightly turns brown from HCl, and a rainbow tint forms from FeCl 3; not pickled by KCN, KOH, HgCl 2, (NH 4) 2 S. Structural features aggregates are detected by etching with HCl (1:1 or 1:5). Microchemically, Pb is determined with KCN on a thin section, S is determined by the imprint method on silver bromide paper. Film reaction: with a saturated solution of J in 5% KJ, when boiled, the mineral turns yellow-green.

Other properties

The mineral conducts electricity. On the face of the octahedron, the electrical conductivity of the mineral is higher than on the face of the cube. The electrical conductivity increases with increasing temperature, but drops sharply above 300° (Niggli). Detects either positive or negative photoelectric effect. Galena with a positive photoelectric effect does not have detector properties; galena, giving a negative photoelectric effect, are good detectors. Diamagnetic.

Behavior of a mineral when heated: Melting point. 1112°. At high temperatures(above 350°) PbS forms solid solutions with AgBiS 2 . Ramdor (1955) explains the high content of Ag in galena, which does not contain microscopically detectable minerals - carriers of Ag. Characteristically, in these cases there is always an appreciable, often equivalent amount of Bi. Thus, in galena formed during medium and elevated temperatures, it can be assumed that matildite is present in the solid solution.

The stone is easily chipped by steps along three mutually perpendicular planes.

Obtaining galena

Easily obtained in various ways (Dölter, 1925), for example, by the action of H 2 S on acidified HNO s solutions of Pb salts (amorphous and crystalline PbS); during the interaction of chloride compounds Pb with dry H 2 S in a heated tube; during the decomposition of lead sulfate in an atmosphere of H 2 or CO; when lead sulfate interacts with rotting organic matter in water, when pyrite or marcasite is heated with a solution of PbCl 2.

Diagnostic signs

The mineral is easily identified by its color, luster, characteristic cube cleavage, low hardness and high density. In fine-crystalline masses, it differs from antimony and arsenic compounds similar to it in density, behavior under a blowpipe and chemical reactions.
In polished sections, the possibility of mixing galena with other common white isotropic minerals is almost excluded, since it clearly differs from them in the main features: reflectivity, color, hardness, and especially in chipping triangles. In fine grains, it can be mixed with altaiite (PbTe), claustalite (PbSe), but the former is significantly, while the latter is only slightly lighter and much softer.

Satellites. Its most typical companion among the hypogene minerals in various deposits is sphalerite - this is the so-called polymetallic ores. ; often accompanied also by pyrite and chalcopyrite. Vein minerals in most hydrothermal deposits are quartz, barite, fluorite, calcite.

Origin and location

Galena is one of the most common sulfide minerals in hydrothermal deposits, formed at various temperatures and in various geological settings. Medium- and low-temperature hydrothermal deposits are of the greatest industrial importance. In the form of small rare grains, the mineral is found in pegmatites of granitic and alkaline magma, as rare mineral- in igneous rocks and volcanic secretions. Hypergene galena has been found in some sedimentary formations. Sometimes the mineral forms almost monomineral ores (as, for example, in the Zavodinskoye deposit in Rudny Altai), but usually it is accompanied by other sulfides.

Mineral change

Easily changed to natural conditions with the formation of cerussite, anglesite, pyromorphite, mimetesite, bedantite, less often - linarite, plumboiarosite, massicot, wulfenite, phosgenite, cotunnite and other minerals. In pseudomorphs after galena are known: cerussite, anglesite, wulfenite, pyromorphite, calamine, limonite, tetrahedrite, chalcocite, rhodochrosite, quartz, pistomesite. The most common replacement of galena by cerussite, sometimes with the release of native sulfur.

Place of Birth

In deposits among skarns in the contact zones of granitoids and sedimentary rocks (mainly limestones), galena forms dissemination and granular aggregates, sometimes found in significant quantities, accompanied by skarn minerals, sphalerite, chalcopyrite, pyrrhotite, etc. Examples: Altyn-Topkan in the Karamazar mountains (Tajikistan ), Tetyukhe (Primorsky Territory), Kyzyl-Espe, Aksoran and Akchagyl (Northern Balkhash region, Kazakhstan), Savinskoye and other deposits of the Chita region, Darwin (California, USA), Schwarzenberg (Saxony, Germany) and others.
In lead-zinc ores forming deposits and veins, galena, in close association with sphalerite, is accompanied by pyrite, chalcopyrite, often arsenopyrite, as well as fahlore, pyrargyrite, stephanite, bournonite, boulangerite and other complex sulfides containing Ag, Pb, Cu . Occasionally it is also accompanied by Ni sulfides and arsenides.

Characteristic hydrothermal, mainly medium-temperature deposits are: lead-zinc deposits of Rudny Altai (Kazakhstan and Altai Territory) - Ridderskoe, Zyryanovskoe, Zmeinogorskoe and others; Sadonskoye vein deposit ( North Ossetia Russia); deposits of the Mehmanin ore field (Azerbaijan); some deposits of the central part of Kazakhstan (Berkara, Maykain, Aleksandrovskoe, Kurgasyn, Azhim); deposits Achisai, Mirgalimsai; in the Karatau mountains (Kazakhstan); in the Chita region, the deposits of the Nerchinsk district (Troitskoye, Smirnovskoye, Kadainskoye); vein deposits of Pribram (Czech Republic), Freiberg and Claustal (Germany), Coeur d'Allen in the state. Idaho; Leadville in Colorado (USA), Sullivan (Canada), Santa Eulalia (Mexico), Broken Hill and Mount Isa (Australia), Bodwin (Burma) and many others.

Relatively low-temperature deposits include the Bleiberg deposit (Austria), some deposits of Silesia (Poland), Rybl (Northern Italy), and deposits of the "lead belt" of the state of Missouri (USA).

In varying amounts, galena is also found in substantially copper deposits (in Russia - Dzhezkazgan, some pyrite deposits of the Urals), in deposits of sulfide-cassiterite formation (Yakutia, Primorsky Territory), in iron ore deposits (Bakalskoye deposit, Chelyabinsk region), in gold ore quartz veins (Berezovskoye deposit, Sverdlovsk region), in tungsten and molybdenum deposits (North-Kounrad, East-Kounrad, Karaobin deposits of Kazakhstan).

Hypergene galena in sedimentary rocks results from reduction by organic substances from lead sulfate or from the action of hydrogen sulfide on solutions of lead salts. Forms crusts and plaques on pyrite and marcasite concretions, disseminated and thin films in coals (Borovichi district, Novgorod region). Found in limestone different ages, in paragenesis with pyrite and marcasite, in the form of grains and crystals. In the Triassic deposits of Mount B. Bogdo (Astrakhan region), galena was found as an interlayer in limestone. It is occasionally observed in rocks of various horizons of the Cambrian-Silurian and Devonian near St. Petersburg.
In cupriferous sandstones and sandy limestones of the Cambrian age, galena is observed as a syngenetic dissemination (upper Lena, Irkutsk region). In the ore-bearing variegated sandstones of the Triassic of the Kemern-Mechernich region (Germany), galena, together with cerussite, chalcopyrite, and copper carbonates in the form of nodules and disseminated dissemination in sandstone, is confined to a certain layer.

relatively common in phosphorite concretions of Podolia (Ukraine); it forms regular cubic crystals or fills irregular cavities inside the concretions, and is also located along their outer parts along the rays of the phosphate substance.

As a modern neoplasm, galena is noted in old mines: together with sphalerite in the form of deposits on iron chains in the mines of Upper Silesia (Poland), on abandoned tools - in crystals up to 12 mm in size in Missouri (USA).

There are known pseudomorphs of galena after cerussite, anglesite, pyromorphite, chalcocite, burnonite, fahlore, and wood.
To some extent, the typomorphic properties of galena from hydrothermal deposits are the appearance of crystals and the content of impurities. Crystals of high-temperature hydrothermal galena are more often of a cubic shape, of lower-temperature ones - of an octahedral shape; high-temperature galena often contains bismuth, lower-temperature ones usually contain Ag and Sb.

Practical use

The most important lead mineral (almost all world production of Pb is associated with the extraction of galena). Along the way, silver, thallium, etc. are extracted from galena ores. Ores are partially processed to obtain lead whitewash and glaze.

Physical research methods

Differential thermal analysis

Main lines on radiographs:

ancient methods. Under a blowpipe on coal, it cracks and scatters in pieces, and quietly melts in a fine powder. Coal near the sample is covered with a yellow coating of PbO with a bluish border (PbCO s). (Se-containing varieties form a reddish-brown coating with a narrow dark border on the coal near the sample; a characteristic, albeit weak, smell is detected due to Se). With soda on charcoal, it gives a Pb bead, which, after prolonged blowing, either completely disappears or, in the presence of Ag, leaves a small Ag bead. Releases SO 2 in an open tube

Crystal optical properties in thin preparations (sections)

Refractive indices 4.015 (C), 3.912 (D), 3.796 (F) (according to Winchel).
In reflected light, white, serves as a reference white color. Reflectivity (in%): for green rays 43.5, for orange - 37.5, for red - 35; according to Folinsby, measured with a photocell - 42.4. Isotropic. Sometimes abnormally anisotropic as a result of pressure or due to the presence of an isomorphic α-AgBiS 2 impurity. Galena is polished well in fine-grained aggregates, worse in coarse-grained ones. A characteristic diagnostic feature is the presence of chipping triangles in polished sections, which are equally oriented within single-crystal grains; the reason for their formation is the perfect cleavage in the cube. Etching or weathering sometimes reveals a fine zonal structure, especially in low-temperature galena.

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Lead sheen, PbS, contains 86-6% lead, is most common in nature, but industrial deposits are rare. PbS is a gray cubic crystal with a density of 74 - 77 g/cm3 and a hardness of 25 - 27 on the Mohs scale.

Lead glitter (or artificial lead monosulfide crystals) is sometimes used as contact detectors.

Lead sheen (galena) is a crystal used in crystal detectors paired with a metal tip. Widely applied artificial crystals WITH.

Lead luster is characterized by: an isometric appearance of crystals (the length, width and height of the crystals are approximately equal to each other), perfect cleavage in a cube, and a very large specific gravity.

Lead gloss concentrates, containing about 60% lead, are calcined together with silicon dioxide in rotary kilns in a stream of air.

Almost every lead luster usually contains a little silver, which dissolves together with nitrate acid. For this reason, he boiled the previously obtained lead lime with caustic ammonia which is one silver, if it is contained. The remainder of this brew, which now should have been only pure lead lime, when sweetened and dried, weighed almost as much as before.

GALENITE (lead luster) - mineral, lead sulfide, PbS; contains impurities of Ag, Zn, Gd, Sb, Bi, Cu, Sn, In, Tl, Au, Pt, etc. Crystallizes into a cube. Occurs in the form of large-crystalline.

GALENITE (lead luster), mineral, lead sulfide PbS, contains 86 6% lead.

Galena (lead luster) PbS - mineral, lead sulfide. It contains Ag, Au, and a number of other elements as impurities.

Galena (lead luster) PbS. The shape of the crystals is most often cubic. It is the main ore for lead.

Large deposits lead luster are found in the USSR in the North Caucasus, in Kazakhstan, in Altai, in the Far East and in other regions. Since lead belongs to the main subgroup of group IV, the outer layer of its atom is formed by 4 electrons.

Only with lead shine No. 1 the thermal effect was significant (comparatively), so that with a light red heat of the heater it could be noticed even with a resistance of 100,000 ohms connected in series with the galvanometer. With the rest of the crystals, with such a resistance, it was impossible to notice any deviation. As we have seen, in the characteristics of Fig. 13 and 14 it is absolutely impossible to notice the influence of the thermal effect. Even less, of course, it could influence the onset of the zincite characteristics shown in Fig. 9, since the heating of the resistance of the contact point was even less. In the generation of oscillations, the thermal effect also cannot be of importance, since recently it was possible to obtain with a zinc kit detector a wavelength of only 68 m23 and there is no reason not to obtain even more short waves. These frequent vibrations are obtained with the same characteristics and in the same area as the low frequency; heating of the detector from the outside and acts similarly on them.

Lead sulfide - lead gloss, galena (PbS), is often found in metamorphic limestones, especially in those that have undergone alteration due to the invasion of igneous rocks into them. Lead sulfide, together with some other sulfides, forms ores of great industrial importance. As a result of oxidation from these ores, equally or even more valuable ores are formed in nature, for example, various oxides, sulfates and carbonates. Native lead is rare. Many lead sulfosalts, lead silicates, lead phosphate, lead arsenate, and several lead vanadates are also known. The most important ore - galena - is often found together with pyrite, marcasite and sphalerite.

Stone Galena or lead shine. A mineral that forms the basis of lead ores.

Galena occurs in quartz and calcite veins (as a rule, together with the zinc mineral - sphalerite). The ores that form galena and sphalerite are called polymetallic, they are a source of many non-ferrous metals, and, above all, lead and zinc.

Galena is a gray, lead-gray mineral with a strong metallic luster. It forms fine cubic crystals, but is more common in solid masses.

The mineral has perfect cleavage - the ability to split in certain directions upon impact. Galena breaks into small cubes, even the finest powders of galena are the smallest cubic grains.

The mineral is soft, heavy, brittle. It melts quite easily, and yellow lead litharge (lead oxide) is formed. It dissolves in hydrochloric acid (in heat), followed by the release of hydrogen sulfide, which has a characteristic smell of rotten eggs.

Galena deposits generally have igneous origin. Formed in hydrothermal veins formed as a result of the consolidation of residual solutions, which are formed during the formation of rocks such as granites and pegmatites. In these cases, the mineral is found in association with sphalerite, argentite, quartz, and fluorite.

Galena stone, in addition, can be formed in sedimentary conditions. It is believed that such deposits are formed due to the concentration of minerals initially dispersed in the rock. Large deposits of galena in limestones and dolomites can have such an origin.

The very rich deposits in America are scattered mineralization. They are located in three states - Missouri, Oklahoma, Kansas. This area is called Tri-State ("three states"), and the most famous center in it is Joplin.

Australian (Brocken Hill), English (Cumberland), Mexican (Eulalia) and German (Andreasberg and Freiberg) deposits are also widely known.

In Italy, there are deposits developed over many centuries - these are Raibl (Carnic Alps), Dossena Mountain (foothills of the Alps in Lombardy), Monteponi and Montevecchio (Sardinia).

Galena is the main ore mineral of lead. Silver is recovered from some silver-bearing galena as a by-product.

Galena has been known to man since ancient times: even during the Punic Wars in Spain, there were mines for the development of lead ores.

During the excavations of Pompeii, lead pipes were found, various products from lead, as well as products painted with white lead. There is an assumption that in the Roman Empire there was an extensive network of water pipes, and its pipes were made of lead.

According to ancient legends, it was widely used in medicine: it healed wounds and was good for the eyes.

When galena powder was smeared on an ulcer, it allegedly corroded "wild meat".

If you grind it in water, it eliminates the smell under the arms, that is, it serves as a deodorant. Therefore, galena was used in antiquity to restore beauty along with blush, etc.

There is an opinion that galena has a beneficial effect on the human body. Its effect is similar to a tonic drink. Galena invigorates and makes its owner cheerful and active.

For the prevention of melancholy and depression, galena is recommended to be worn in earrings.