Brown spar or ''brown-spar'' ()''Krivovichev V. G.'' Mineralogical glossary. Scientific editor A. G. Bulakh. — St.Petersburg: St.Petersburg Univ. Publ. House. 2009. — 556 p. — ISBN 978-5-288-04863-0 is a

trivial Trivia is information and data that are considered to be of little value. Modern usage of the term ''trivia'' dates to the 1960s, when college students introduced question-and-answer contests to their universities. A board game, ''Trivial Purs ...

, partly obsolete name for at least ''four''

carbonate mineral Carbonate minerals are those minerals containing the carbonate ion, . Carbonate divisions Anhydrous carbonates *Calcite group: trigonal **Calcite CaCO3 **Gaspéite (Ni,Mg,Fe2+)CO3 **Magnesite MgCO3 **Otavite CdCO3 **Rhodochrosite MnCO3 **Sider ...

s that are relatively similar in composition:

ankerite Ankerite, also known as '' brown spar''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 A ...

, dolomite (with varieties),

magnesite Magnesite is a mineral with the chemical formula ( magnesium carbonate). Iron, manganese, cobalt, and nickel may occur as admixtures, but only in small amounts. Occurrence Magnesite occurs as veins in and an alteration product of ultramafic r ...

(with varieties) and

siderite Siderite is a mineral composed of iron(II) carbonate (FeCO3). Its name comes from the Ancient Greek word (), meaning "iron". A valuable iron ore, it consists of 48% iron and lacks sulfur and phosphorus. Zinc, magnesium, and manganese commonly ...

,Bulletin of the United States National Museum. No.30. Published under the Directions of the Smithsonian Institution. — Washington: Government Printing Office, 1885. which have a characteristic dirty-brown hue due to the content of

iron Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's o ...

compounds, as well as an admixture of

manganese oxide Manganese oxide is any of a variety of manganese oxides and hydroxides.Wells A.F. (1984) ''Structural inorganic chemistry'' 5th edition Oxford Science Publications, . These include * Manganese(II) oxide, MnO * Manganese(II,III) oxide, Mn3O4 * Man ...

. As a consequence, many varieties of dolomite, colored brown or grey-brown by impurities, are also known as ''brown spar''. The name brown spar is both capacious and vividly descriptive, referring exclusively to the appearance of the stones; short and convenient for everyday conversational use, it was approximately equally characteristic of both English-language and German mineralogy until the end of the 19th century. However, even later this stable phrase remained in the speech of miners, geologists and other craft specialties — as a colloquial term of broad or not entirely definite meaning, applicable to three or even four different minerals.''Georgy Shcherbina''. Mountain English-Russian Dictionary. — Moscow, Vologda: Infra-Engineering, 2022. — 784 p.

Main minerals and varieties

Ankerite Ankerite, also known as '' brown spar''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 A ...

is a mineral, a complex

carbonate A carbonate is a salt of carbonic acid, (), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate group ...

from the dolomite group, in which some of the

magnesium Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 ...

ions are replaced by

, calculated formula Ca(Fe,Mg,Mn)(CO₃)₂. The chemical composition is sometimes complicated by impurities of

manganese Manganese is a chemical element; it has Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese was first isolated in the 1770s. It is a transition m ...

and

cobalt Cobalt is a chemical element; it has Symbol (chemistry), symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. ...

. The ferrous member of the dolomite-ankerite isomorphic series, structurally close to dolomite. * 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) can also be found under the name brown spar. *

Siderite Siderite is a mineral composed of iron(II) carbonate (FeCO3). Its name comes from the Ancient Greek word (), meaning "iron". A valuable iron ore, it consists of 48% iron and lacks sulfur and phosphorus. Zinc, magnesium, and manganese commonly ...

is a

hydrothermal Hydrothermal circulation in its most general sense is the circulation of hot water (Ancient Greek ὕδωρ, ''water'',Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with th ...

sedimentary Sedimentary rocks are types of rock formed by the cementation of sediments—i.e. particles made of minerals (geological detritus) or organic matter (biological detritus)—that have been accumulated or deposited at Earth's surface. Sedime ...

mineral, in composition

iron carbonate Iron(II) carbonate, or ferrous carbonate, is a chemical compound with formula , that occurs naturally as the mineral siderite. At ordinary ambient temperatures, it is a green-brown ionic solid consisting of iron(II) cations and carbonate anions ...

with the ideal formula FeCO₃, depending on the amount and nature of impurities, has a color from white or yellowish-white to reddish-brown. Dirty-colored differences of brown shades are known as brown spar.'' Lodotshnikov V. N.'' The main rock-forming minerals. — Moscow:

Nedra ''Nedra'' is a genus of moths of the family Noctuidae The Noctuidae, commonly known as owlet moths, cutworms or armyworms, are a family (biology), family of moths. Taxonomically, they are considered the most controversial family in the superfa ...

, 1974. — 248 p. *

Magnesite Magnesite is a mineral with the chemical formula ( magnesium carbonate). Iron, manganese, cobalt, and nickel may occur as admixtures, but only in small amounts. Occurrence Magnesite occurs as veins in and an alteration product of ultramafic r ...

(ferrous) or breunnerite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. is a mineral common in the earth's crust from the class of carbonates with the chemical composition MgCO₃. Among the most common impurities found in magnesite are the same

ions (Fe²⁺) or

, which give the white or translucent mineral a cloudy red or brown color. In such cases, it can also be called ''brown spar''. * Mesitine spar ( mesitite),'' Brush, George Jarvis'' (1875). Manual of Determinative Mineralogy: with an introduction on blow-pipe analysis. — New York : John Wiley & Son, 1875. or '' breunnerite'' — a

carbonate of iron Iron(II) carbonate, or ferrous carbonate, is a chemical compound with formula , that occurs naturally as the mineral siderite. At ordinary ambient temperatures, it is a green-brown ionic solid consisting of iron(II) cations and carbonate anions ...

and

, occurring in yellowish

rhombohedron In geometry, a rhombohedron (also called a rhombic hexahedron or, inaccurately, a rhomboid) is a special case of a parallelepiped in which all six faces are congruent rhombi. It can be used to define the rhombohedral lattice system, a honeycomb w ...

s. This includes much of what is called rhomb spar ( rhombic spar), or brown spar, which becomes rusty on exposure.'' Dana, James Dwight'' (1853). Manual of Mineralogy: Including Observations on Mines, Rocks, Reduction of Ores and the Application of the Science to the Arts. — Durrie and Peck (5th edition), 1853. * Mesitine spar ( pistomesite),'' Justus Freiherr von Liebig''. Annual Report of the Progress of Chemistry, and the Allied Sciences, Physics, Mineralogy, and Geology. — Taylor, Walton, and Maberly, 1850. — 646 p. — another brown variety of the

→

isomorphic series, formerly known as mesitite or brown spar and containing a greater amount of

than mesitite and breunnerite.

Brown spar gallery

Ankerite, Pyrite - Goldmyer Hot Springs, King Co, Washington, USA.jpg, Dolomite hg.jpg, Siderite iron ore.jpg, Magnesite1.jpg, Magnesite var. Breunnerite detail.jpg, Mesitite.jpg,

References

{{Set index article Set index articles on minerals Iron minerals Magnesium minerals Calcium minerals Manganese minerals Mining terminology Mineral groups

Main minerals and varieties

Brown spar gallery

See also

References