Magnesite serves as the basis for the production of binders and refractory substances, in particular, refractory bricks. It is used by the chemical, pharmaceutical and even jewelry industries.
What is magnesite
The term “magnesite” refers to magnesium carbonate. Outwardly, it somewhat resembles marble.
The formula of the substance is MgCO3. The real composition of the mineral is very close to the formal one. Almost half of the mass is magnesium oxide, a little more is carbon dioxide. Magnesite contains impurities such as iron, calcium, and magnesium.
The mineral may have a gray, white, brownish or yellowish color. It has a glassy or matte sheen. The crystals are quite dense and can have different grain sizes. There are even porcelain-shaped crystals that contain admixtures of magnesium silicate and opal.
Magnesite got its name from the Greek region of Magnesia. It was there that its deposits were discovered in ancient times.
One of the most popular types is caustic magnesite, which is formed by firing raw materials at a temperature of around 700 degrees. The main share in its composition is occupied by magnesium oxide.
Caustic magnesite is divided into three classes based on composition. Material of the 1st class is used by the chemical industry, 2nd and 3rd – by the construction industry.
Photo different types magnesite
Caustic magnesite Stone magnesite
Magnesite slabs
Magnesite slabs are a fundamentally new building material made on the basis of magnesite. They are made in the form of sheets 3-12 mm thick. They are produced in lengths of 1.83-2.44 m and widths of 0.9-1.22 m.
Magnesite plate includes several layers:
- external;
- fiberglass mesh, which provides good stability and strength;
- filler;
- fiberglass reinforcing layer;
- filler on the inside.
The filler is a composite material, which is made by mixing magnesium oxides and chlorides, silicates, organic fibers, plasticizers, etc.
Properties and characteristics
Magnesite is a rather brittle material. Its hardness is 4-4.5. The hardness of porcelain material is slightly higher - about 7. Density varies from 2.97 to 3.10 g/cm3. It dissolves poorly in water, but well in chlorine.
To mix caustic magnesite, not water is used, but a solution of magnesium sulfate or magnesium chloride. The result is magnesium cement. If the material is mixed with water, it will harden for a long time, and its strength will not be very good.
The final strength of the substance is quite high. A solution of caustic magnesia has a strength of up to 100 kg/cm2. Maximum strength is achieved after about a week if hardening occurs under normal conditions.
The hardening of caustic magnesia is determined by the fineness of grinding and firing temperature. The material sets in a minimum of 20 minutes and a maximum of 6 hours after mixing.
Features of magnesite slabs
Magnesite slabs absorbed everything best qualities magnesite. Their density is approximately 0.95 g/cm3. The thermal conductivity coefficient is 0.21 W/m. They can withstand heating up to 1200 degrees. The sound insulation level reaches 46 dB. Water resistance reaches up to 95%.
The advantages of magnesite slabs are:
- moisture resistance – when immersed in water, they do not swell for up to 100 days;
- fire resistance – a 6 mm thick sheet holds fire for 2 hours;
- environmental friendliness - even when heated, no toxins are released;
- frost resistance;
- good sound and heat insulation;
- high degree of plasticity - they can be bent, reaching a radius of curvature of up to 3 m;
- impact resistance;
- light weight - 1 m2 of average thickness weighs about 6.04 kg.
- no odor;
- Possibility of use for finishing public premises.
Magnesite boards - the building material of the future:
Magnesite production
The production of the material includes the extraction of raw materials, crushing, roasting and grinding. This mineral is usually found in deposits with metamorphosed dolomite. Also, together with gypsum, it is found in salt-bearing sedimentary rocks and certain igneous rocks.
Magnesite is mined in European countries such as the Czech Republic, Germany, Italy, and some areas of Poland and Austria. There are deposits of magnesite in North Korea, China, India, Mexico and the United States. In our country, this mineral is mined in the Orenburg and Chelyabinsk regions, in the Middle Volga region, in Far East. The Savinskoye field in the Irkutsk region is the largest in Russia and the world.
Mining is usually carried out in quarries using the explosive method. The blocks are crushed into fragments with a diameter of 150 to 300 mm right at the extraction site, after which they are sorted into three grades according to hardness and purity. Firing is carried out in ovens various types. Typically, rotating or shaft devices with remote fireboxes are used.
After firing at 700-1000 degrees, up to 94% of carbon dioxide is lost, and caustic magnesia is formed in the form of a chemically active powder. If the firing temperature is increased to 1500 degrees, burnt magnesia will be obtained. It has low activity, but a very high level of fire resistance.
After firing, the raw materials are ground in ball or other mills. Caustic magnesite must be crushed so that when passing through sieve No. 02, no more than 2% remains, and through sieve No. 008 - a maximum of 25%. To prevent the substance from hydrating, it is packaged in metal drums.
How magnesite slabs are made can be seen in the video:
Application
Magnesite is used as a fine filler in construction mixtures. It is used to make fire-resistant bricks that can withstand heating up to 3000 degrees, artificial marble, magnesite plaster, and fire-resistant paints.
It is used in the production of sugar, paper, electrical insulators, pharmaceuticals, etc. Since magnesite is an ore of magnesium, it is used to obtain magnesium and its salts.
Caustic magnesite is used for the production of binding cements, artificial rubber, viscose, and plastics. It is an important component in the manufacture of thermal insulation materials, in the pulping process, a good fertilizer, etc.
Burnt magnesia is used primarily in the metallurgical industry. Using special furnaces, fused periclase is made from it. This is a material with excellent thermal and electrical insulating parameters, which is used in the manufacture of ceramics.
Magnesia cement is used to create warm, seamless floors filled with sawdust. They are resistant to abrasion, have low thermal conductivity, are durable and are characterized by complete hygiene.
Use of magnesite slabs in construction
Magnesite slabs serve as finishing materials for:
- wall cladding from the inside and outside;
- installation of ceilings, floors, partitions between rooms;
- manufacturing fences;
- installation of a soft roof;
- finishing of swimming pools, baths, bathrooms;
- furniture assembly;
- making banners and billboards;
- arrangement of hotel complexes, schools, etc.
Magnesite slabs have excellent technical qualities. The most important advantage we can assume that they allow you to carry out repairs without “wet” finishing processes.
Magnesite slabs are distinguished by their hygiene, radiation safety, fire resistance and good sound insulation. Due to their resistance to moisture, they can be used in finishing bathrooms, swimming pools, etc.
The slabs are easy to process. They can be cut with a hacksaw or knife, drilled, fastened with screws or nails. The slabs can be coated with any paint, tiles, wallpaper, etc. can be glued to them.
Installation of magnesite slabs does not require any special skills. They are mounted either on a metal or wooden frame. Fastening is usually done using self-tapping screws. Since the slabs are attached to the frame, there is space between them and the wall. This provides additional thermal insulation of the room.
If desired, the boards can be attached directly to the wall using glue. In this simple way you can easily level the surface.
The only drawback of magnesite slabs is that if they are small in thickness, they are particularly fragile.
Magnesite plate and possibilities of its use
Composition of magnesite plate Methods of application
Pros and cons of the material
The main advantage of magnesite is the ability to mix it with various natural and artificial fillers. Using magnesite as a binding component, you can make concrete with both mineral and organic filler, for example, sawdust or shavings. The introduction of magnesite into the mixture makes the material resistant to rotting.
Caustic magnesite has good properties in terms of strength, thermal insulation and service life. It is mineral in nature and has a uniform texture.
The disadvantage of magnesite is its poor resistance to moisture. If air humidity reaches 75%, the material begins to swell greatly. The material can only be stored in well-closed containers. When lying for a long time, it begins to lose its qualities.
|
Properties |
Magnesite | |
|
Chemical formula | ||
|
Varieties |
Brainerite, siderite |
Nemalite, ferrobrucite, mangan-brucite |
|
MgO – 47.6; CO 2 – 52.4 |
MgO – 69.0; H 2 O – 31 |
|
|
singonia |
Trigonal |
Trigonal |
|
Appearance |
Crystalline aggregates, less often earthy and amorphous forms |
Crystalline, dense, leafy, scaly, rarely fibrous aggregates |
|
White gray |
White, grey, bluish green |
|
|
Glass, dim |
Mother of pearl, glass |
|
|
Density, g/cm 3 | ||
|
Hardness | ||
|
Cleavage |
Perfect |
Very perfect, mica-like |
|
Fragility |
Splits into plates and fibers |
|
|
Dissociation temperature, o C | ||
|
Ud. magnetic susceptibility |
–0.38 10 –3 |
Diamagnetic |
|
Electrical conductivity, Ohm..m | ||
|
The dielectric constant |
Pyroelectric dielectric |
|
|
Solubility |
Decomposes when heated in acids |
Decomposes in acids |
|
Luminescence |
In UV - blue, in cathode - crimson |
In UV - bluish, dark crimson |
In industry, magnesite is used mainly after preliminary firing. When fired to 750–1000 °C, magnesite loses 92–94% CO 2 and turns into magnesium oxide, which is a white amorphous powdery mass (caustic magnesite). At a higher firing temperature (up to 1500–1700 °C), almost all carbon dioxide is removed, magnesium oxide undergoes a restructuring of the molecular structure and a dense sintered inert product is formed, called “tightly” fired magnesite or refractory magnesia.
Firing of magnesite to obtain “tightly” fired magnesite (sintered powders) is carried out in shaft and rotary kilns. Waste from firing is represented by caustic magnesite, formed from dusty particles deposited in dust chambers and multicyclones, carried by the gas flow from the causticization zone of furnaces (750–1000 °C). Caustic magnesite, in addition to amorphous magnesium oxide, contains both unburned and fired magnesite at temperatures above 1000 ° C, as well as fuel ash as impurities.
At temperatures up to 2800 °C in electric arc furnaces, magnesium oxide melts and fused periclase is formed, which has a crystalline structure, high hardness and fire resistance, used for the production of especially critical refractory products.
Cheaper periclase of high purity is obtained from brucite with similar processing.
5. The use of magnesite is due to the combination of favorable physical and chemical properties of products obtained from it: high fire resistance, slag resistance, astringent properties, heat capacity, the ability to maintain constant volume under prolonged exposure to high temperatures, strength, wear resistance. The following products are mainly used, obtained using different production technologies: caustic magnesite with a MgO content of 75–90%, tightly fired (sintered powders with a MgO content of 86–92%) and electrofused periclase (with a MgO content of 95–97%). These products are used to produce a wide range of materials and products for various industries.
The main consumer of magnesite (over 80%) is the refractory industry. Sintered metallurgical powders or fused periclase obtained from magnesite after firing or melting are used for the manufacture of magnesite, chromium-magnesite, magnesite-chromite refractory products, which are used for laying open-hearth, electric smelting and other high-temperature furnaces and for lining rotary cement kilns. Metallurgical magnesite powder is also used for welding the bottoms of steel-smelting furnaces and for their repair.
During the firing process at high temperatures, the impurities contained in natural magnesite combine with magnesium oxide and form new minerals. A particularly harmful impurity is calcium oxide. When there is an excess of it, free lime is present in refractories, which can hydrate with a sharp increase in volume, which causes cracks to appear and sometimes complete destruction of the product. An admixture of silica with a small amount of calcium leads to the formation of forsterite, which is poorly resistant when exposed to slags and temperatures above 1750 °C. With a significant calcium content and a CaO:SiO 2 ratio of less than 1.87 (in moles), insufficiently refractory and resistant minerals are formed in the products - monticellite and merwinite (CaO MgO SiO 2 and 3CaO MgO 2SiO 2).
An admixture of alumina in an amount of up to 5–8% promotes the formation of a spinel binder, which increases the thermal resistance of magnesite products under sudden temperature changes without a noticeable decrease in refractory properties. The presence of iron oxide also leads to the formation of a binder, but a significant decrease in fire resistance is observed. Alumina and iron oxides are usually present in magnesite-based refractory products in small quantities, and therefore their content is not taken into account by the regulatory indicators of state standards and technical specifications.
The second most important consumer of magnesite is the production of cementitious materials, where caustic magnesite is used (with a MgO content of at least 75%, CaO not more than 4.5%, SiO 2 not more than 3.5%, F 2 O 3 + Al 2 O 3 not more than 3.5% and p.p. not more than 18%). Caustic magnesite with a concentrated solution of magnesium chloride or sulfate forms magnesium cement (“Sorel cement”), which has high astringent properties. This cement is used for the production of various construction materials (fiberboard, xylolite, etc.), thermal insulation, sound insulation materials, artificial millstones and abrasive wheels. Metallic magnesium, magnesium phosphates are obtained from caustic magnesite, burnt magnesia is produced to produce rubber products, and also magnesium sulfate for the production of chemicals and pharmaceuticals.
In the electrical industry, magnesite (in the form of periclase) is used in the production of ceramics used for the manufacture of radio components, as a filler in tubular electric heaters, to obtain press-in mass in household electric heating devices and for other electrical purposes.
Magnesite is also used as a fluxing additive in the production of certain types of porcelain and earthenware, and sanitary ceramics.
In the pulp and paper industry, magnesite is used as a weakly alkaline reagent in pulping, for processing paper under presses, and as a filler for film coatings of paper.
In the food industry, magnesium oxide hydrate Mg(OH) 2 is used in sugar refining.
In addition, magnesite has found application in the production of plastics, absorbents, paints, glassware, fertilizers and other industries.
6. Brucite is a rather unique magnesium raw material due to its composition and technological processing features. When fired, it is less energy intensive than magnesite, and, in addition, when it decomposes, water is released that does not pollute natural environment. Brucite is used both raw and burnt. In its raw form, its use is very effective as a weakly alkaline reagent in the production of cellulose due to multiple turnover and the absence of discharge of liquors into water bodies. During firing, the dissociation of brucite occurs at a lower temperature than magnesite, and the fired product has very high electrical properties due to an insignificant amount of impurities and is electrical periclase of the highest quality. Electric melting produces a very dense aggregate with increased thermal conductivity and electrical insulating properties. Caustic magnesia, obtained from brucite, is highly reactive and is suitable for producing a wide range of magnesia chemical products used in many industries.
Compared to domestic use, brucite is used very widely abroad, including in the production of viscose, plastics, uranium hydrometallurgy, sugar refining, winemaking, coating of welding electrodes, production of ceramic products, thermal insulation materials, glass products, structural materials for electronic, nuclear and rocket equipment, infrared and ultraviolet optics, fuel additives, water and gas purification, paper filler, ornamental material, etc.
There are no special technical requirements for the quality of brucite; the quality of products obtained from it is assessed according to state standards and technical specifications for products obtained from magnesite or for products from other industries.
7. There are no uniform requirements for the quality of magnesite used in industry. The requirements of various industries for these raw materials and the resulting products, depending on the field of application, are regulated by the relevant state standards and technical specifications approved in the prescribed manner.
For the production of refractories, magnesite is used containing at least 42% magnesium oxide, no more than 2.5% calcium oxide and no more than 2% silica. Magnesite with a magnesium oxide content of at least 38% can be used to produce magnesium binders and some other purposes.
To obtain fused periclase and periclase-based refractories, high-quality magnesites (with a MgO content of at least 45.5%) and brucites containing at least 62% magnesium oxide, no more than 3% calcium oxide and no more than 3% silica can be used. To obtain electrical periclase and in pulp and paper production, magnesite with a MgO content of at least 46% and brucite with a magnesium oxide content of at least 65%, calcium oxide no more than 1.0%, silica no more than 8.0% and iron oxide no more than 0.2%.
Currently, with the improvement of metallurgical processes, the requirements for the quality of raw materials, and in particular, for the content of impurities in commercial magnesia, are being tightened. Thus, high-quality refractory magnesia must contain at least 98% MgO (after firing), and for critical types - more than 99%. At the same time, impurities of iron oxides that were not previously standardized now play a role important role in the evaluation of raw materials and commercial products. All types of commercial magnesia are differentiated precisely by the content of MgO and Fe 2 O 3, although the requirement for a low content of Fe 2 O 3 is of limited importance, and in the production of some refractory products, on the contrary, iron oxides are introduced as mineralizers, so there are commercial grades with high iron content
8. According to the conditions of formation, magnesite deposits belong to two formation types - terrigenous-carbonate and ultramafic.
The terrigenous carbonate formation type is associated with continental and marine sediments and is divided into the supergene sedimentary continental genetic type and the supergene sedimentary marine genetic type.
The main source of magnesite is deposits of sedimentary marine type associated with terrigenous-carbonate (dolomite) complexes belonging to a wide age interval - from the Precambrian to the Mesozoic. They are located in miogeosynclinal zones framing cratons.
Domestic deposits are divided into Riphean (Satkinskoye in the Urals, Kirgiteyskoye, Verkhoturovskoye, Talskoye and others in the Krasnoyarsk Territory, Safonikhinskoye in the Far East) and Early Proterozoic (Savinskoye and Onotskoye in the Irkutsk region). The deposits are usually represented by very large (length up to a kilometer or more, thickness of tens and hundreds of meters) sheet- and lens-shaped deposits of high-quality crystalline magnesites. Early Proterozoic deposits are characterized by a high degree of metamorphism and, as a consequence, the presence of silicates in magnesites (talc, enstatite, forsterite, brucite, etc.).
Continental sedimentary magnesite deposits are confined to channel or lacustrine facies developed in depressions or drainless depressions located either directly on ultramafic massifs subject to weathering or in close proximity to them. Similar Cenozoic deposits are known in Turkey, Greece, and Serbia. A very large deposit of this type has been discovered in Australia with reserves of hundreds of millions of tons.
The ultramafic formation type is divided into hypogene and supergene genetic types. The first is represented by talc-magnesite stone, which makes up very large deposits. However, the quality of the ores is not high, due to the increased content of harmful impurities, especially iron, and therefore are not used for the production of critical products. There are deposits in the Urals (Syrostanskoye, Shabrovskoye, Veselyanskoye). Supergene deposits are associated with the weathering crusts of ultramafic rocks and are represented by vein, stock-shaped, nest-shaped bodies of pelitomorphic magnesite of a rather complex configuration, the variability of the qualitative composition, which predetermines the difficulties of their exploitation. In Russia, the Khalilovskoye deposit in the Orenburg region is known.
Deposits of monomineral brucite are very rare in the world (only a few), one of them – Kuldurskoe – is located in Russia in the Far East. The deposits are hydrothermal-metasomatic and have direct genetic connection with magnesites and formed along them in zones of contact metamorphism under the influence of hypabyssal and subvolcanic intrusions. The extent of ore bodies in contact aureoles is measured in hundreds of meters and thickness – tens of meters. The quality of raw materials is usually very high.
In Russia, deposits of crystalline magnesites of the sedimentary-metamorphic type are being developed (in the Chelyabinsk region and Krasnoyarsk Territory), the Khalilovskoye deposit of pelitomorphic magnesites in the Orenburg region (weathering crust of ultrabasic rocks) - only for the production of caustic magnesite, and the Kuldurskoye brucite deposit in the Jewish Autonomous Okrug (hydrothermal-metasomatic type ).
/ mineral Magnesite
Magnesite is a common mineral, anhydrous magnesium carbonate from the calcite group. It is part of a solid solution with siderite (FeCO3) and gaspeite (NiCO3). Syn: magnesium spar. The flame does not color. It dissolves in acids only when heated. A drop of HCl does not boil in the cold. Dissolves in hot acids. Chem. composition: magnesium oxide (MgO) 47.6%, carbon dioxide (CO 2) 52.4%. Impurities of iron, manganese, calcium. The crystal structure is the same as calcite. Some of these accumulations are formed hydrothermally. This primarily includes fairly large deposits of crystalline-granular masses of magnesite, spatially associated with dolomites and dolomitized limestones. As geological studies show, these deposits are formed metasomatically (among the deposits it was sometimes possible to identify relics of limestone fauna). It is assumed that magnesia could be leached and deposited in the form of magnesite by hot alkaline solutions of dolomitized strata of sedimentary origin. Typical hydrothermal minerals are occasionally found in paragenesis with magnesite. Accumulations of cryptocrystalline (“amorphous”) magnesite also arise during weathering processes of massifs of ultrabasic rocks, especially in cases where intense weathering results in the formation of a thick crust of destruction products. During the process of oxidation and hydrolysis, magnesium silicates undergo complete destruction under the influence of surface water and air carbon dioxide. The sparingly soluble iron hydroxides that arise accumulate at the surface. Magnesium in the form of bicarbonate, as well as released silica (in the form of sols), sink into the lower horizons of the weathering crust. Magnesite, often enriched in opal and dolomite, is deposited in the form of veinlets and accumulations of sintered forms in highly leached fractured porous serpentinites in the zone of stagnant groundwater. Finally, finds of magnesite with hydromagnesite (5MgO.4CO2.5H2O), mostly of mineralogical significance, are observed among sedimentary salt-bearing deposits. The formation of magnesium carbonates is associated with the reaction of exchange decomposition of magnesium sulfate with Na2CO3. The famous Satka deposit of crystalline magnesite of hydrothermal origin is located on the western slope of the Southern Urals (50 km southwest of the city of Zlatoust). Large magnesite deposits were formed here metasomatically among the dolomite sedimentary strata of Precambrian age. Similar deposits are known in the Far East, Southern Manchuria, Korea, Czechoslovakia, Austria (Weitsch, in the Alps, south of Vienna) and other places. It is formed together with talc during metamorphism (Shabrovskoe deposit, Middle Urals) and weathering of ultrabasic rocks (Eubea island in the Aegean Sea, Greece. Deposits formed in the ancient weathering crust of ultrabasic rocks include Khalilovskoe (Southern Urals) and the island of Euboea in the Aegean Sea, Greece. It is an ore of magnesium and its salts; used for the production of refractories and binders, in the chemical industry; used for the production of refractory bricks. When extracting magnesite, only limited use is made of mechanical (manual and using photocell and laser devices), and sometimes also flotation and electromagnetic enrichment. At a temperature of 750-1000°C, chemically active powder, the so-called, is obtained from magnesite. caustic, magnesia, from which CO2 has not yet been completely removed. At 1500-2000°C, refractory magnesia is obtained, which consists mainly of periclase (MgO) crystals with a melting point of about 2800°C. At elevated temperature(up to 3000°C), especially pure fused periclase is obtained in electric furnaces. The most widespread product of magnesite processing, refractory magnesia, is used primarily in metallurgy. Caustic magnesia is used in chemical processing processes (weakly alkaline reagent, catalyst, etc.), as a fertilizer, for feeding livestock, in special cements, in the production of cellulose for gas purification, in the manufacture of filters, etc., for the production of viscose and synthetic rubbers , paints (fireproof filler), sugar and sweets, in winemaking, glassmaking, ceramics (fluxes), electric heating rods, water and gas purification, in uranium processing, as an anti-corrosion additive to petroleum fuels, etc. Magnesite is used quite widely in the jewelry industry. This stone can be painted, so a variety of jewelry is made from it. Magnesite is colored to resemble red coral, lapis lazuli, and turquoise.Varieties of mineral
Magnesite, compared to calcite, is much less common in nature, but is sometimes found in large continuous masses of industrial interest.Place of Birth
Sedimentary magnesite is deposited in lakes and lagoons, interbedded with dolomite or mixed with anhydrite. The largest deposits are in the strata of lagoon-marine dolomites: magnesite layers up to 500 m thick and tens of kilometers long (Satkinskoye in the Urals, deposits of the Liaodong Peninsula, China).Practical significance
report an error in the description
Properties of the Mineral
| Color | Colorless, white, gray-white, yellowish, brown, lilac-pink; colorless in internal reflexes and at random. Crystals often have an uneven zonal-sectoral distribution of color. |
| Stroke color | white |
| origin of name | In the region of Magnesia (Thessaly, Greece), where it was first discovered. |
| Opening place | Magnisia Prefecture (Magnesia), Thessalia Department (Thessaly), Greece |
| Opening year | 1808 |
| IMA status | approved |
| Chemical formula | MgCO3 |
| Shine | glass matte |
| Transparency | transparent translucent |
| Cleavage | perfect by (1011) |
| Kink | conchoidal uneven stepped |
| Hardness | 3,5 4 4,5 |
| Thermal properties | Doesn't melt, cracks. |
| Luminescence | May exhibit pale green to pale blue fluorescence and phosphorescence |
| Typical impurities | Fe,Mn,Ca,Co,Ni,ORG |
| Strunz (8th edition) | 5/B.02-30 |
| Hey"s CIM Ref. | 11.3.1 |
| Dana (8th edition) | 14.1.1.2 |
| Molecular weight | 84.31 |
| Cell Options | a = 4.6632Å, c = 15.015Å |
| Attitude | a:c = 1: 3.22 |
| Number of formula units (Z) | 6 |
| Unit cell volume | V 282.76 ų |
| Twinning | Sometimes there may be |
| Point group | 3m (3 2/m) - Hexagonal Scalenohedral |
| Space group | R3c (R3 2/c) |
| Density (calculated) | 3.01 |
| Density (measured) | 2.98 - 3.02 |
| Pleochroism | visible |
| Optical axis dispersion | very strong |
| Refractive indices | nω = 1.700 nε = 1.509 |
| Maximum birefringence | δ = 0.191 |
| Type | single-axis (-) |
| Optical relief | moderate |
| Selection form | Obtuse rhombohedral crystals, usually found in dense, granular, earthy, chalky, amorphous porcelain-shaped aggregates (cauliflower-shaped or brain-shaped). |
| Classes on taxonomy of the USSR | Carbonates |
| IMA classes | Carbonates |
| singonia | trigonal |
| Fragility | Yes |
| fluorescence | Yes |
| Literature | Anfimov L.V., Busygin B.D. South Ural magnesite province. Sverdlovsk: IGG UC USSR Academy of Sciences, 1982. – 70 p. Anfimov L.V., Busygin B.D., Demina L.E. Satkinskoye field in the Southern Urals. M.: Nauka, 1983. – 86 p. Vitovskaya I.V. etc. Nickel magnesite from the Saryku-Boldy deposit (Central Kazakhstan) is the first discovery in the USSR. –Doc. Academy of Sciences of the USSR, 1991, 318, No. 3, 708-711. |
Minerals Catalog
