Where is lime spar used?

Lime spar or calcite – a mineral representing the carbonate salt of lime of crystalline composition. Chemical CaCO formula₂ (56,0% CaO and 44,0% CO₂), but mostly contains, as an isomorphic mixture, MgCO₃ and FeCO₃. Due to the extraordinary ability to form well-developed crystals, the extreme variety of shapes (at present, there are over two hundred scalenohedra with rhombohedrons, and the number of combinations is about seven hundred), and furthermore, very pronounced crystallographic and physical properties, I. spar played a prominent role in the development of mineralogy ; in all fairness, one can say: “The history of lime spar is at the same time the history of mineralogy.” I. spar crystals belong to the rhombohedral division of the hexagonal system. Its most common forms are: 1) hexagonal prism of the 1st kind (c) with a basopinacoid (o) (Fig. 1) – crystals sometimes take the form of thin hexagonal tablets. 2) Rhombohedron of the 1st kind of sign – 1 /₂R (0112) with polar angles of 134°57′ (Fig. 2, g). 3) Scalenohedron R3 (2131) (Fig. 3, r) with angles of 144°24′ and 104°38′ in the polar ribs. 4) A rhombohedron with angles of 105°5′, called the main rhombohedron (Fig. 4, P), although it is rare, this form is very easy to obtain by breaking any I. spar crystal. The twinning formation of crystals is very common and occurs according to many laws, but twins are more often observed according to two: 1) the twinning plane is the basopinacoid oR (twins with a parallel system of axes); in this case, the planes of rhombohedrons or scalenohedrons form alternating reentrant angles lying in the plane of the lateral axes (Fig. 5); sometimes both rhombohedrons, fused according to this law, grow into each other, forming twins of germination, in which trihedral pyramids protrude on each plane of one rhombohedron , making up the trihedral angles of another rhombohedron. 2) Door the plane is the plane of the so-called first obtuse negative rhombohedron – 1 /₂R (0112), and double. axis – normal to it; In this way, twins with inclined systems of axes are formed (Fig. 6). According to this law, polysynthetic twins are very often formed, in which the middle indivisibles are shortened so much that they take the form of thin plates, the boundaries of which are indicated by rectilinear streaking parallel to the diagonal of the rhombuses on two opposite planes of the rhombohedron. Lamellar polysynthetic composition is constantly observed in granular aggregates, can be easily recognized under a microscope in polarized light and, according to Inostrantsev, serves as a sharp difference between calcite and dolomite grains. In all likelihood, the double structure of granular calcite aggregates arose after their formation as a result of pressure, since it does not occur in samples that were subjected to more or less strong pressure in mountain ranges (for the artificial production of this kind of twins, see Double). Very perfect cleavage follows the planes of the main rhombohedron. Hardness 3. Specific gravity 2,6-2,8; in pure difference – 2,72. Transparent and colorless crystals exhibit an extraordinary ability to become electrified under pressure. The color of I. spar varies (white, gray, yellow, green, etc.), or it is completely colorless. Transparent to varying degrees. The so-called Icelandic or doubling spar is particularly pure, transparent and colorless (see Birefringence). The luster is glassy, ​​and sometimes pearlescent on the cleavage planes. It does not melt in front of a blowpipe; when heated, it glows strongly, turning into caustic lime. In hydrochloric acid at ordinary temperatures it easily dissolves with effervescence, which differs from dolomite, which requires heating to dissolve. Dissolves in appreciable quantities in water containing carbonic acid; From this solution, upon evaporation, crystals of i. spar are released at low temperatures in the form of basic rhombohedrons; in the presence of various impurities, various other forms appear. In nature, I. spar extremely rarely appears in the form of a basic rhombohedron. At higher temperatures, as well as from very dilute solutions, aragonite predominates. Due to its solubility, CaCO₂ is, one might say, in all the waters flowing in rocks. Under suitable conditions, it is distinguished in various modifications of I. spar: stalactites and stalagmites are formed in caves, tuffs form at the bottom of lakes or swamps, pea stones, travertino, etc. are formed from hot springs. In the same way, pseudomorphoses of I. are also frequent. spar for various minerals; for aragonite (so-called paramorphoses), anhydrite, gypsum, barite, fluorspar, cerusite orthoclase, garnet; back – various minerals according to I. spar, for example, quartz, brown iron ore, red iron ore, pyrite, lead luster, feldspar, chlorite, iron spar, cerusite, malachite, etc. Especially often, I. spar serves as a petrifying substance for animals and plants remains – corals, crinoids, mollusk shells, trees, etc. The best crystals of I. spar, which are always overgrown, very often in the form of druses, are found along the walls of cracks, voids of I. mountains, almond-shaped volcanic rocks, in ore veins, etc. Number There are very many deposits of good crystals. But the crystals from Gelgastad in Iceland are especially famous for their purity and size; this is the so-called Icelandic doubling spar; they are found in voids up to 12 m long. and 5 m wide in black almond stones. This deposit supplies almost all the material for optical devices that require polarized light. Among other deposits that also contain good crystals of I. spar, although inferior to Icelandic ones, one can point to the ore veins of the Harz (Andreasberg), the Ore Mountains in Saxony (Freiberg, Schneeberg, etc.) and Bohemia. Also the surroundings of Chemnitz, Pribram. In the Alps – Bleiberg, Arenthal, St. Gotthard, Traversell, etc. In Italy, good crystals are found near Bologna; in France – Monteneblo; in Norway, Conesbury and Arendal are famous; in England and Scotland lead deposits of Cornwallis, Derbyshire, Devonshire, etc.; all in. America is rich in crystal copper deposits on Lake Superior. In Russia: in the Urals, the Turinsky and Kirabinsky mines: in the Crimea, in the vicinity of the Baydarsky Gate; in Altai in the Zmeinogorsk mine and some others; in the Transbaikal region in the mines of the Nerchinsk region. In addition to clearly formed crystals, I. spar forms continuous masses of the most varied structure, sometimes forming very large accumulations and thus constituting rocks. These include marbles, limestones, I. tuffs, etc. (see corresponding names). Liter. Bournon, “Traité complet de la chaux carbonatée” (1808); Lippe, “Denkschrift. Wien. Akademie” (Bd. 3, 1851); Des-Cloizeaux, “Manuel de Mineralogie” (vol. II, 1874); Irby, “On the crystallography of calcite” (Bonn, 1878); Koksharov, “Material. z. Miner. Russl.” (Bd. 7); Cezaro, “Ueber belgische Kalkspäthe” (“Mem. de l’akademie R. de Belgigue”, 1886).

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Lime spar or calcite – a mineral from the class of natural carbonates, one of the natural forms of calcium carbonate (CaCO₃). Widely distributed in the earth’s crust in several forms:

• as a rock-forming mineral – limestone, chalk, marl, carbonatite;
• as a natural crystal in various modifications – aragonite, vaterite and others;
• as the most common biomineral, it is the main mineral component of the shells (and endoskeletons) of many invertebrate animals, calcareous algae and bones.

Lime spar in brief quotations[edit]

At the bottom of rivers you can find lapis lazuli. Mineralogists searched in vain for the deposit of this expensive stone; the foreigner More lived for this purpose for two summers on the Slyudyanka River, spent a lot of money and finally deceived the Yekaterinburg mining authorities with the imaginary discovery of a deposit of lapis lazuli <.>in the places indicated by More, prehnite or blue lime spar turned out to be. [1]

. one comes across dark gray limestone, followed by a harder one – white and, finally, closer to White Irkut – huge strata of calcareous spar, organized in the form of large light orange crystals. It forms entire mountains, giving a special, original character to the upper reaches of the Irkut, since the rock weathers very easily, forms bell-shaped spikes, needles, many caves and huge bright placers. [2]

. Next to the fossilized parts of the shells of Devonian fish, there are accumulations of tree-like spore-like plants of that period impregnated with iron oxide and lime spar. [3]

In places they were pierced by white veins of calcareous spar and quartz, sometimes scattering like a network, sometimes merging into one whole. [4]

The purest CaCO₃ forms transparent crystals of lime or Iceland spar, widely used in optics. [5]

Lime spar in scientific and popular science literature[edit]

Near the so-called Cheeks, 250 versts below Kirensk, the left bank is formed by calcareous rocks containing veins of siliceous rock and lime spar crystals. These rocks are constantly multiplying at a distance of 350 versts above the city of Olekma, near which the banks again decrease and become low-lying. They contain numerous fragments of green porphyry, simple quartz with glimmer sparkles and glimmer slate in great quantities. [6]

On the tops of the Baikal mountains you can find granite, lava and rock crystal; below – lime spar with deposited molybdenum, talc, baicalite, prehnite, and in some places dark mica in tables. At the bottom of rivers you can find lapis lazuli. Mineralogists searched in vain for the deposit of this expensive stone; the foreigner Mor lived for this purpose for two summers on the Slyudyanka River, spent a lot of money and finally deceived the Yekaterinburg mining authorities with the imaginary discovery of a deposit of lapis lazuli. Craftsmen and tools for making vases, tabletops, etc. were sent to Irkutsk, but they had to return with nothing: in the places indicated by More, there was prehnite or blue lime spar. [1]

To the north of the guard lie conglomerates or, rather, huge strata (about 50 m, 165 feet) of poorly compacted pebbles and gravel with cement made of red clay, of a homogeneous composition with the pebbles now deposited by Irkut. Their layers lie on the southern side on gneisses and mica schists, and on the north on granites, crystalline schists and light gray limestones, which finally, 10 versts from the guard, become the predominant rock. So, one comes across dark gray limestone, followed by a harder one – white and, finally, closer to White Irkut – huge strata of calcareous spar, organized in the form of large light orange crystals. It forms entire mountains that give a special, original character to the upper reaches of Irkut, since the rock weathers very easily, forms bell-shaped spitz, needles, many caves and huge bright placers falling towards Irkut. The Irkut carries away limestones in its fast current, dissolves them and deposits limescale on all the boulders that move its waters. Anyone who has visited mountainous countries, where the traveler encounters at every step only metamorphic schists and granites, will easily understand how difficult it is to trace the bedding and fall of strata and how little one can rely on certain directions in which strata fall, made only along one particular line. [2]

At the top of the Butogolsky char, mainly granites emerge. They consist of smoky quartz, the same feldspar, black mica and hornblende. In some places they protrude above this cape in dense masses, but in other parts at the top of the char you see only masses of crumbling granite, accumulating mainly on the eastern side. Beneath these collapsed granites, graphite lies in coarse crystalline calcareous spar. G. Radde testifies that it is in them that pieces of graphite are mainly found, with obvious plant imprints. [2]

What is certain is that a comparative geological study of the upper reaches of Irkut, Kitoy, Oka and Belaya will lead to the solution of many significant questions about the formation of the mountain systems of Central Asia. The mineralogist and geognosticist, of course, will also find a lot of interesting things – I will point out, for example, the spread of metamorphism through huge strata of limestone and other shales, to entire mountains of lime spar, mainly near Munku-Sardyk. [2]

. Having hired horses, I headed up Dzhunbulak. The valley of the lower reaches of this river runs remarkably straight for about 12 versts, as if it were stretched along a cord between two rows of almost vertical mountains. At first we encountered limestones, intruded by granites, then grayish gneisses, and finally, about 12 versts from the guard, the same coarsely crystallized lime spar, orange-colored, that we encountered in the upper reaches of the Irkut. [2]

The deposits of the Devonian system extend first wide and then narrowly hollow to the northeast along the above-mentioned boundary of the gneiss massif and are represented in the lower section by highly altered sandstones and quartzites (Shoksha quartzite), in the middle by limestones with numerous remains of Devonian mollusks and fish, in the upper ― brightly colored sandstones and sands, where, next to the fossilized parts of the shells of Devonian fish, there are clusters of tree-like spore plants of that period impregnated with iron oxide and lime spar. [3]

Calcium carbonate CaCO₃ – one of the most common compounds on Earth. Minerals based on CaCO₃ cover about 40 million square kilometers of the earth’s surface. Chalk, marble, limestone, shell rocks – all this is CaCO₃ with minor impurities, and calcite is pure CaCO₃. <.>In their pure form, limestones are white or light yellow, but impurities give them a darker color. The purest CaCO₃ forms transparent crystals of lime or Iceland spar, widely used in optics. And ordinary limestones are used very widely, in almost all sectors of the national economy. [5]

We are accustomed to the fact that a physical concept is expressed in numbers. How can this be done in relation to hardness? One very artisanal, but at the same time practically useful method has long been used by mineralogists. Ten specific minerals are arranged in a row. Diamond comes first, followed by corundum, then topaz, quartz, feldspar, apatite, fluorspar, limespar, gypsum and talc. The series is selected as follows: a diamond leaves a scratch on all minerals, but none of these minerals can scratch a diamond. [7]

Lime spar in fiction and fiction[edit]

The engineers went down one by one. It was also light and relatively spacious here. All around rose the walls of the mine, still free of support and consisting of alternating thick and thin layers of various sandstones of red-brown and dirty green color, lying horizontally on top of each other, like giant sheets of multi-colored cardboard. In places they were pierced by white veins of calcareous spar and quartz, sometimes scattering like a network, sometimes merging into one whole. Water flowed down the walls in drops and streams, glistening like diamond crystals under the rays of an electric lantern suspended from the platform. [4]

Along the black walls of the shaft, bristling with thin slate tiles, water flowed everywhere, dripped into puddles, and sparkled with lights under the rays of a lantern. Here and there, whimsically sinuous snow-white veins of lime spar and quartz stood out sharply against the gloomy background. Light steam came from the walls and from the pit with water, and the air in the shaft was saturated with it, like in a bathhouse, and was just as hot, despite the fact that icy air was blown in from numerous holes along the periphery of the platform, blowing around the walls. [4]

Outcrops near the Amagu River (Capes Belkin and Arka) deserve special attention. Here, in the motley layers of tuff, you can see voids with concretions of lime spar and some kind of soft greenstone. Nautical charts show two coastal gates at these locations. Some small ones are near the shore, others large ones are in the water. Nowadays only those closer to the shore have survived. <.>
At about twelve o’clock in the afternoon we were near the large rock Mafa, which means “bear” in Udehe. Indeed, in its shape it is very reminiscent of it and consists of dense sandstone with layers of quartz and calcareous spar. [8]

They heard sometimes short and sometimes longer blows coming from the depths of the earth, as if there, somewhere far away, the work of huge forges was going on; it seemed as if heavy hammers were hitting hard metal. The rock trembled slightly, and one could see how from time to time individual crystals of the lime spar that made up the marble were torn off from the white wall. [9]

Sources [edit]

1. ↑ 12N. S. Shchukin. Sea or Lake Baikal. Location and size of Lake Baikal; the waters flowing in and out of it; islands; underwater rocks; capes; harbors; characteristics of the surrounding mountains. – St. Petersburg: Journal of the Ministry of Internal Affairs, part 23, 1848.
2. ↑ 12345Peter Kropotkin. “A trip to the Oka guard.” Scientific heritage. Volume 25. – M.: Nauka, 1998.
3. ↑ 12N. I. Berezin, “Walking along Karelian waterfalls” with 60 drawings by the artist I. S. Kazakov and original photographs of the author, with 5 cards in the text. – St. Petersburg: Printing house of the Public Benefit Partnership, 1903, 193 p.
4. ↑ 123Obruchev V.A. “Journey to the past and future”: stories and stories. ― M.: Nauka, 1965
5. ↑ 12B. I. Skirstymonskaya. Calcium. – M.: “Chemistry and Life” No. 6, 1969
6. ↑F.P. Wrangel, “Travel to Siberia and the Arctic Sea.” – L.: Publishing house of the Main Northern Sea Route, 1948.
7. ↑A. I. Kitaygorodsky, L. D. Landau. Physics for everyone. – M.: Nauka, 1984.
8. ↑VC. Arsenyev. “Along the Ussuri region.” “Dersu Uzala.” — M.: Pravda, 1983.
9. ↑Obruchev V.A. Plutonium. Sannikov land. – M.: Mechanical Engineering, 1982.

See also [edit]

• Wikipedia article
• Meanings in Wiktionary
• Texts on Wikisource
• Media files at Wikimedia Commons

• Spars
• Calcium
• Carbonate
• Mineralogy
• Thematic articles in alphabetical order

• Wikiquote: Link to Wikipedia directly in the article
• Articles with links to Wiktionary
• Wikiquote: Link to Wikisource directly in the article
• Wikiquote: Link to Wikimedia Commons directly in the article