Myths and legends

Why is hornblende called that?

Hornblende (the name is a tracing paper with it. Hornblende ) is a rock-forming igneous mineral of the amphibole group of the subclass of ribbon silicates of complex chemical composition. Common hornblende is a complex aluminosilicate of calcium, magnesium and iron. Forms black short-columnar crystals with a hexagonal cross-section, dark green granular aggregates, pseudomorphs after pyroxene (uralite), disseminated grains. Widely distributed, it forms many igneous and metamorphic rocks. When weathered, it turns into clay minerals, limonite, and carbonates.

Place of Birth

It is widespread, but the most famous are beautiful examples from Norway (Rent), the Czech Republic (the vicinity of Pilsen), and Italy (lavas of Vesuvius).

См. также

  • Amphiboles
  • Rock-forming minerals
  • Koksharovit

references

Hornblende on Wikimedia Commons?
  • Hornblende in the mineral catalog
  • Hornblende on Geowikipedia
  • Hornblende: description and photo on the minerals portal
  • Hornblende in the mineral determinant
  • Minerals in alphabetical order
  • Silicates (minerals)
  • Calcium minerals
  • Magnesium minerals
  • Iron minerals
  • Rock-forming minerals

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Useful

See what “Hornblende” is in other dictionaries:

  • Hornblende – 1. ml, syn. common hornblende. 2. Name subgr. calcium amphiboles, combining common hornblende, edenite, tschermakite, pargasite and ferrogastingsite. Geological Dictionary: in 2 volumes. M.: Nedra. Edited by K.N. . Geological Encyclopedia
  • HORNBLENDE – a rock-forming mineral of a subclass of chain (ribbon) silicates of complex chemical composition. Dark green (to black) elongated crystals, solid granular masses. Hardness 5,5 6,0; density 3,1 3,3 g/cm³. An important part. . Big Encyclopedic Dictionary
  • hornblende – noun, number of synonyms: 8 • anthophyllite (2) • calamite (4) • carintin (1) • . Dictionary of synonyms
  • HORNBLENDE – – mineral of the amphibole group. Common hornblende is a typical mineral of granitoids, gabbroids and metamorphic rocks. Often formed due to pyroxene, and magnetite is often released. Basaltic hornblende (oxidized) -. . Paleomagnetology, petromagnetology and geology. Dictionary-reference book.
  • hornblende – a rock-forming mineral of a subclass of chain (ribbon) silicates of complex chemical composition. Dark green (to black) elongated crystals, solid granular masses. Hardness 5,5 6,0; density 3,1 3,3 g/cm3. An important component of many. . Encyclopedic Dictionary
  • hornblende — raginukė statusas T sritis chemija apibrėžtis Mineralas. formulė Formulę žr. Priede. priedas( ai) Grafinis formatas atitikmenys: engl. hornblende rus. hornblende … Chemijos terminų aiškinamasis žodynas
  • Basaltic Hornblende – ml, calcium amphibole with a high Fe3+ : Fe2+ ratio and low content. (HE) . Ca2(Na,K)0,5 1,(Mg,Fe2+)3 4(Fe3+,Al)2 l × (O,OH,F)2[Al2Si6O22]. Brown to black. Ch. arr. in effusive p. Syn.: oxidized hornblende. Geological Dictionary . Geological Encyclopedia
  • HORNBLEADE – ml, essentially calcium amphibole (Ca,Na,K)2 3(Mg,Fe2+,Fe3+, Al)3[(OH,F)2|(Si,Al)2Si6O22]. The composition is not constant. There are continuous isomorphic series between R. o. O. and tschermakite, edenite, pargasite, ferrogastingsite, tremolite. Mon. Gab. . Geological encyclopedia
  • HORNBLIDE OXIDIZED – ml, sin. Basaltic hornblende. Also called hornblende with oxygen instead of (OH), and in which Fe2+ is oxidized. Geological Dictionary: in 2 volumes. M.: Nedra. Edited by K. N. Paffengoltz et al. 1978 . Geological Encyclopedia
  • Hornblende — 1) the most common rock-forming mineral from the group of monoclinic amphiboles (See Amphiboles) (R. o. vulgaris). Approximate chemical composition Ca2Na [Mg, Fe]4 [Al, Fe] [(Si, Al)4O11]2[OH, F]2, with significant fluctuations. . Great Soviet Encyclopedia
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Hornblende (hornblende) is a group name for a number of minerals of the amphibole group. The name is not a very successful translation from German horn – horn, blenden – to blind. Hornblende traditionally includes any dark-colored amphiboles.

The main characteristic feature of the chemical composition of the minerals of the hornblende group is the high calcium content: from 1,5 to 2,3 atoms per formula unit. In addition, hornblende contains moderate amounts of sodium and smaller amounts of potassium. The aluminum content varies greatly in the different minerals of this group, but generally ranges from 1 to 3 atoms per formula unit; silicon is replaced by no more than two aluminum atoms. Thus, the hornblende group includes aluminous calcium amphiboles, which are a multicomponent solid solution in which three isomorphic series are distinguished, determined by independent substitutions: 1. Si → Al iv, 2. Mg → Fe 2+, 3. □ → Na, K. They are connected with alumina-free calcium amphiboles (tremolite – actinolite) by a gradual transition; the conventional boundary is drawn at Al iv = 0.50. A gradual transition connects hornblende with sodium-calcium amphiboles due to the substitution of Ca + (Mg,Fe 2+) → Na + (Al,Fe 3+); the conventional boundary is drawn at Ca=1.34. With amphiboles of the cummingtonite-anthophyllite series, in which the place of Ca in position B is filled with Mg and Fe 2+, hornblende forms continuous solid solutions only at high temperatures. The composition of hornblende, taking into account possible fluctuations in the content of the main components and isomorphic substitutions, is expressed by the formula (Na,K)0-1[(Ca,Fe 2+ ,Mn,Mg)2-1.34Na0-0.66] (Mg,Fe 2+ ,Mn,Al,Fe 3+ ,Ti)5 [And7.5-5.3Al0.5-2.7](O,OH)22(OH,F,Cl,O)2.

Nomenclature

The nomenclature used for aluminous calcium amphiboles is extremely ambiguous. Ordinary hornblende is usually called the most common hornblende in nature with medium alumina content. Common hornblende has the formula (Ca, Na, K)2-3(Mg,Fe 2+,Fe 3+,Al)5[And6(Si,Al)2O22](OH,F)2. In addition to significant fluctuations in the ratios of the main components, isomorphism of Ba, Rb is possible; Ca, TR, Y, Sr, U, W, Mo, Ga, Li, Zn, Sc). Sometimes all hornblende except basaltic ones are called common. According to the 1997 nomenclature (Leake et al., 1997), 19 end members (end members) are distinguished among aluminous calcium amphiboles:

  • Edenite – Ferro-edenite
  • Pargasite – Ferropargasite
  • Magnesiohastingsite – hastingsite
  • Chermakite – Ferrochermakite, Alyumochermakite – Aluminum-ferrochermakite, Ferrichermakite – Ferry-ferrochermakite
  • Magnesiosadanagaite – Sadanagaite
  • Magnesiohorblend – Ferrochorblend
  • Kersutite – Ferrokersutite
  • Canilloit

Materials

Monoclinic system. Forms elongated prismatic and irregular grains, fibrous aggregates of green, black, brown color. Hardness on the mineralogical scale is 5,5-6. Density 3100-3300 kg/m3. Glass shine. Characterized by perfect cleavage in two directions at an angle of 124°. Fragile. The fracture is stepwise and uneven. The line is green in different shades.

Finding

Common hornblende is characteristic of intrusive (granodiorites, syenites, diorites, hornblende gabbros), effusive (andesites, basalts, porphyrites), as well as metamorphic (amphibolites, etc.) rocks.

Secondary changes

Common hornblende is a relatively stable mineral, but under the influence of hydrothermal solutions it turns into chlorite, epidote, calcite and quartz; during weathering, it decomposes to form opal, carbonates and other minerals.

Literature

  • Plechov P.Yu., Tsai A.E., Shcherbakov V.D., Dirksen O.V. Hornblende in andesites of the March 30, 1956 eruption of Bezymianny volcano and the conditions of their opacitization. – Petrology, 2008, v. 16, 1, pp. 21-37.
  • Silicates with ribbons of silicon-oxygen tetrahedra // Minerals Directory, Publishing House “Nauka”, Moscow 1981, vol. III, issue 3, pp. 100-103.
  • Leake BE et al. Nomenclature of amphiboles: report of the Subcommittee on Amphiboles of the International Mineralogical Association Commission on New Minerals and Mineral Names // Am. Mineral., 1997, Vol. 82, no. 9-10, p. 1019-1037.
  • Deere W.A., Howie R.A., Zusman J. “Rock Forming Minerals”, Volume 2, Chain and Band Silicates

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