Bitter spar

Bitter spar or bitter-spar () is a trivial, partly obsolete name for at least two carbonate minerals that are relatively similar in composition: dolomite (with varieties) and magnesite (with varieties).Brockhaus and Efron Encyclopedic Dictionary: in 86 volumes (82 volumes and 4 additional volumes). — St. Petersburg, 1890-1907. - Volume IX (1893): Goa — Engraver, p. 359: from the article Bitter spar; Supplementary Volume Ia (1905): The Hague Conference — Kochubey, p. 607 The name «bitterspar» was given primarily due to its content of magnesium carbonate, MgCO, which is the basis for obtaining bitter (Epsom) salt or magnesia. There is also a popular belief that the name directly reflects the taste of the mineral: if you lick the crystals of this feldspar, they may seem bitter.

History and properties According to geochemical concepts that had formed by the end of the 18th century, bitter spar was considered a type of bitter limestone with an inconstant composition. For example, bitterspars from the Austrian Tyrol, according to the results of chemical analysis, contained 52% carbonate of lime, 45% carbonate of bitter earth and 3% carbonate of iron oxide, thus representing a mixed carbonate of magnesium and calcium with a noticeable content of coloring impurity of iron compounds. It has generally been noted that crystals of bitterspar, as a rule, have a rhombohedral shape and their properties generally correspond to those of calcite spar crystals, slightly surpassing them in hardness and resistance to acid attack. Bitterspars are most often found embedded in chlorites, Serpentinites, or talcs, where they are a typical hydrothermal mineral.N. P. Yushkin, O. K. Ivanov, V. A. Popov; Introduction to the topominerology of the Urals. — M.: Nauka, 1986. Sometimes bitter feldspars are also found in cracks and voids of basalt massifs.

During the first third of the 19th century, the best-quality bitterspars were mined in Tyrol, around Salzburg, and in the St. Gotthard Pass mines. In the Miemo region of Tuscany, good-quality bitterspars were found as inclusions within gypsum blocks.

In the Urals, bitter spar was first discovered by Mohr in 1813 near the village of Rashkina, near the Polyakovsky mine, near the Verkhneyvinsky plant, and again in 1815 at the Berezovsky mines. It is widespread and is a common mineral in hydrothermal veins in serpentinites (Bazhenovo, Izumrudnye Kopi). In the Saranovsky massif, it occurs in veins up to 30 cm thick, with antigorite and in pseudomorphs after calcite. Quite good specimens have been repeatedly recovered from the southern Urals, from the banks of the Uya River, where bitterspar regularly forms veins in chlorites. Near the Miass plant, it is found in talc, where it has a radiating structure and was known in the 19th century as miascite. In Siberia, solid bitterspar mixed with chlorite grains forms bizarre translucent intergrowths and is called listvenite.

In many mineralogical sources from the 17th and 19th centuries, the traditional name bitterspar appears as a synonym or variety for all or some brown feldspars, which chemically represent minerals of the dolomite-magnesite series with coloring iron impurities, as well as manganese oxide. Specifically, in 19th-century literature, the name bitterspar regularly appears to refer to both brown spars in general and certain identified varieties, including even mesitite.Robert Brough Smyth. Mining and Mineral Statistics. A Catalogue of Foreign Minerals, in the possession of Mining Department, Melbourne, Victoria. Compiled by W. Vazie Simons, F.C.S., London, and Published by direction of the honorable the minister of mines. — John Ferres, Government Rinter, Melbourne. 1859.

For example, in his student dissertation of 1856, Dmitri Mendeleev wrote about this fundamental mineralogical problem with all certainty:Dmitri Mendeleev. Isomorphism in connection with other relationships of crystalline form to composition. Dissertation presented at the end of the course at the Main Pedagogical Institute by student D. Mendeleyev. — St. Petersburg: type. I.I. Glazunov and Comp., 1856. — 234 p.

Attempts at more precise chemical analysis and the separation of concepts date back to the second half of the 19th century. Alexander Henry Green in a large work on geology intended for students and a wide range of readers interested in science, wrote:Alexander H. Green. Geology for Students and General Readers: Part I. Physical geology. — London: Daldy, Isbister, & Co. 56, Ludgate Hill, 1876.

Main minerals and varieties Magnesite, or bitter sparGeorgy Shcherbina. Mountain English-Russian Dictionary. — Moscow, Vologda: Infra-Engineering, 2022. — 784 p. in the clear-crystalline modification,The Small Brockhaus and Efron Encyclopedic Dictionary: in 3 volumes. — St. Petersburg: Brockhaus-Efron, 1899-1902. — volume II, issue. 3 (1909): Kign — Cob, stem. 430: from the article Magnesite is a mineral widely distributed in the earth′s crust from the class of carbonates with the chemical composition MgCO. Among the most common impurities found in magnesite are iron (Fe2+) or manganese ions, which give the white or translucent mineral a cloudy reddish or brown color. In such cases, magnesite is more often known as brown spar. Dolomite, or bitter spar, is a mineral common in the earth's crust from the class of carbonates with the chemical composition CaCO3•MgCO3, varieties close to dolomite from the same isomorphic series, colored brown or dirty brown by iron and manganese impurities (ferriferous dolomite)礦物學名詞: (俄英中对照試用本) Mineralogical Terminology (Russian-English-Chinese version). — Beijing: 中國科学院. 編譯出版委員会 Compilation and Publication Committee of Chinese Academy of Sciences, 1956. — 279 p. can also be found under the name brown spar. Brown spars in general and mesitite (the best known of them) in particular,Brush, George Jarvis (1875). Manual of Determinative Mineralogy: with an introduction on blow-pipe analysis. — New York : John Wiley & Son, 1875. are a conventional collective name for at least two carbonate minerals that are relatively similar in composition: ankerite,R. A. Lidin, L. L. Andreeva, V. A. Molochko, edited by R. A. Lidin. Constants of inorganic substances: handbook. 3rd ed., reprinted. — Moscow: Drofa, 2008. — 685 p. and siderite,Bulletin of the United States National Museum. No.30. Published under the Directions of the Smithsonian Institution. — Washington: Government Printing Office, 1885. which in the mineralogical texts of the 18th and 19th centuries appear systematically under the name of bitter spar.

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Bitter spar

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