Mineral hydration

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In inorganic chemistry, mineral hydration is a reaction which adds water to the crystal structure of a mineral, usually creating a new mineral, commonly called a hydrate .

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In geological terms, the process of mineral hydration is known as retrograde alteration and is a process occurring in retrograde metamorphism. It commonly accompanies metasomatism and is often a feature of wall rock alteration around ore bodies. Hydration of minerals occurs generally in concert with hydrothermal circulation which may be driven by tectonic or igneous activity.

Processes

There are two main ways in which minerals hydrate. One is conversion of an oxide to a double hydroxide, as with the hydration of calcium oxide—CaO—to calcium hydroxide—Ca(OH)2, the other is with the incorporation of water molecules directly into the crystalline structure of a new mineral. [1] The later process is exhibited in the hydration of feldspars to clay minerals, garnet to chlorite, or kyanite to muscovite.[ citation needed ]

Mineral hydration is also a process in the regolith that results in conversion of silicate minerals into clay minerals.[ citation needed ]

Some mineral structures, for example, montmorillonite, are capable of including a variable amount of water without significant change to the mineral structure.[ citation needed ]

Hydration is the mechanism by which hydraulic binders such as Portland cement develop strength. A hydraulic binder is a material that can set and harden submerged in water by forming insoluble products in a hydration reaction. The term hydraulicity or hydraulic activity is indicative of the chemical affinity of the hydration reaction. [2]

Examples of hydrated minerals

Examples of hydrated minerals include:

See also

Related Research Articles

<span class="mw-page-title-main">Mineral</span> Crystalline chemical element or compound formed by geologic processes

In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.

<span class="mw-page-title-main">Hornblende</span> Complex inosilicate series of minerals

Hornblende is a complex inosilicate series of minerals. It is not a recognized mineral in its own right, but the name is used as a general or field term, to refer to a dark amphibole. Hornblende minerals are common in igneous and metamorphic rocks.

<span class="mw-page-title-main">Magnesium hydroxide</span> Inorganic compound of formula Mg(OH)2

Magnesium hydroxide is the inorganic compound with the chemical formula Mg(OH)2. It occurs in nature as the mineral brucite. It is a white solid with low solubility in water (Ksp = 5.61×10−12). Magnesium hydroxide is a common component of antacids, such as milk of magnesia.

<span class="mw-page-title-main">Brucite</span> Magnesium hydroxide mineral

Brucite is the mineral form of magnesium hydroxide, with the chemical formula Mg(OH)2. It is a common alteration product of periclase in marble; a low-temperature hydrothermal vein mineral in metamorphosed limestones and chlorite schists; and formed during serpentinization of dunites. Brucite is often found in association with serpentine, calcite, aragonite, dolomite, magnesite, hydromagnesite, artinite, talc and chrysotile.

<span class="mw-page-title-main">Wüstite</span> Iron(II) oxide mineral formed under reducing conditions

Wüstite (FeO) is a mineral form of iron(II) oxide found with meteorites and native iron. It has a grey colour with a greenish tint in reflected light. Wüstite crystallizes in the isometric-hexoctahedral crystal system in opaque to translucent metallic grains. It has a Mohs hardness of 5 to 5.5 and a specific gravity of 5.88. Wüstite is a typical example of a non-stoichiometric compound.

Cement chemist notation (CCN) was developed to simplify the formulas cement chemists use on a daily basis. It is a shorthand way of writing the chemical formula of oxides of calcium, silicon, and various metals.

<span class="mw-page-title-main">Chlorite group</span> Type of mineral

The chlorites are the group of phyllosilicate minerals common in low-grade metamorphic rocks and in altered igneous rocks. Greenschist, formed by metamorphism of basalt or other low-silica volcanic rock, typically contains significant amounts of chlorite.

<span class="mw-page-title-main">Cummingtonite</span> Silicate mineral

Cummingtonite is a metamorphic amphibole with the chemical composition (Mg,Fe2+
)
2
(Mg,Fe2+
)
5
Si
8
O
22
(OH)
2
, magnesium iron silicate hydroxide.

<span class="mw-page-title-main">Artinite</span> Hydrated basic magnesium carbonate mineral

Artinite is a hydrated basic magnesium carbonate mineral with formula: Mg2(CO3)(OH)2·3H2O. It forms white silky monoclinic prismatic crystals that are often in radial arrays or encrustations. It has a Mohs hardness of 2.5 and a specific gravity of 2.

<span class="mw-page-title-main">Serpentinization</span> Formation of serpentinite by hydration and metamorphic transformation of olivine

Serpentinization is a hydration and metamorphic transformation of ferromagnesian minerals, such as olivine and pyroxene, in mafic and ultramafic rock to produce serpentinite. Minerals formed by serpentinization include the serpentine group minerals, brucite, talc, Ni-Fe alloys, and magnetite. The mineral alteration is particularly important at the sea floor at tectonic plate boundaries.

<span class="mw-page-title-main">Lime (material)</span> Calcium mineral

Lime is an inorganic material composed primarily of calcium oxides and hydroxides, usually calcium oxide and/or calcium hydroxide. It is also the name for calcium oxide which occurs as a product of coal-seam fires and in altered limestone xenoliths in volcanic ejecta. The International Mineralogical Association recognizes lime as a mineral with the chemical formula of CaO. The word lime originates with its earliest use as building mortar and has the sense of sticking or adhering.

<span class="mw-page-title-main">Hydromagnesite</span> Hydrated hydroxy-carbonate mineral of magnesium

Hydromagnesite is a hydrated magnesium carbonate mineral with the formula Mg5(CO3)4(OH)2·4H2O.

Alite is an impure form of tricalcium silicate, Ca3SiO5, sometimes formulated as 3CaO·SiO2, typically with 3-4% of substituent oxides. It is the major, and characteristic, phase in Portland cement. The name was given by Törnebohm in 1897 to a crystal identified in microscopic investigation of Portland cement. Hatrurite is the name of a mineral that is substituted C3S.

An AFm phase is an "alumina, ferric oxide, monosubstituted" phase, or aluminate ferrite monosubstituted, or Al2O3, Fe2O3 mono, in cement chemist notation (CCN). AFm phases are important hydration products in the hydration of Portland cements and hydraulic cements.

<span class="mw-page-title-main">Layered double hydroxides</span> Class of ionic solids characterized by a layered structure

Layered double hydroxides (LDH) are a class of ionic solids characterized by a layered structure with the generic layer sequence [AcB Z AcB]n, where c represents layers of metal cations, A and B are layers of hydroxide anions, and Z are layers of other anions and neutral molecules. Lateral offsets between the layers may result in longer repeating periods.

<span class="mw-page-title-main">Concrete degradation</span> Damage to concrete affecting its mechanical strength and its durability

Concrete degradation may have many different causes. Concrete is mostly damaged by the corrosion of reinforcement bars due to the carbonatation of hardened cement paste or chloride attack under wet conditions. Chemical damages are caused by the formation of expansive products produced by various chemical reactions, by aggressive chemical species present in groundwater and seawater, or by microorganisms. Other damaging processes can also involve calcium leaching by water infiltration and different physical phenomena initiating cracks formation and propagation. All these detrimental processes and damaging agents adversely affects the concrete mechanical strength and its durability.

<span class="mw-page-title-main">Népouite</span> Nickel ore from the serpentine family (phyllosilicate)

Népouite is a rare nickel silicate mineral which has the apple green colour typical of such compounds. It was named by the French mining engineer Edouard Glasser in 1907 after the place where it was first described, the Népoui Mine, Népoui, Poya Commune, North Province, New Caledonia. The ideal formula is Ni3(Si2O5)(OH)4, but most specimens contain some magnesium, and (Ni,Mg)3(Si2O5)(OH)4 is more realistic. There is a similar mineral called lizardite in which all of the nickel is replaced by magnesium, formula Mg3(Si2O5)(OH)4. These two minerals form a series; intermediate compositions are possible, with varying proportions of nickel to magnesium.

The mineralogy of Mars is the chemical composition of rocks and soil that encompass the surface of Mars. Various orbital crafts have used spectroscopic methods to identify the signature of some minerals. The planetary landers performed concrete chemical analysis of the soil in rocks to further identify and confirm the presence of other minerals. The only samples of Martian rocks that are on Earth are in the form of meteorites. The elemental and atmospheric composition along with planetary conditions is essential in knowing what minerals can be formed from these base parts.

<span class="mw-page-title-main">Gyrolite</span> Rare phyllosilicate mineral crystallizing in spherules

Gyrolite, NaCa16(Si23Al)O60(OH)8·14H2O, is a rare silicate mineral (basic sodium calcium silicate hydrate: N-C-S-H, in cement chemist notation) belonging to the class of phyllosilicates. Gyrolite is also often associated with zeolites. It is most commonly found as spherical or radial formations in hydrothermally altered basalt and basaltic tuffs. These formations can be glassy, dull or fibrous in appearance.

Ekplexite is a unique sulfide-hydroxide niobium-rich mineral with the formula (Nb,Mo)S2•(Mg1−xAlx)(OH)2+x. It is unique because niobium is usually found in oxide or, eventually, silicate minerals. Ekplexite is a case in which chalcophile behaviour of niobium is shown, which means niobium present in a sulfide mineral. The unique combination of elements in ekplexite has to do with its name, which comes from a Greek world on "surprise". The other example of chalcophile behaviour of niobium is edgarite, FeNb3S6, and both minerals were found in the same environment, which is a fenitic rock of Mt. Kaskasnyunchorr, Khibiny Massif, Kola Peninsula, Russia. Analysis of the same rock has revealed the presence of two analogues of ekplexite, kaskasite (molybdenum-analogue) and manganokaskasite (molybdenum- and manganese-analogue). All three minerals belong to the valleriite group, and crystallize in the trigonal system with similar possible space groups.

References

  1. 1 2 3 4 5 6 7 8 Rivkin, A.S.; Howell, E.S.; Vilas, F.; Lebofsky, L.A. (2002). "Hydrated Minerals on Asteroids: The Astronomical Record" (PDF). Asteroids III. doi:10.2307/j.ctv1v7zdn4.23. ISBN   9780816522811 . Retrieved 2018-03-10. Hydrated minerals include both silicates and nonsilicates in the scope of this review. Phyllosilicates (or "clay minerals") are commonly found on Earth as weathering products of rocks or in hydrothermal systems. Nonsilicate hydrated minerals include such species as the oxides brucite and goethite, the carbonate hydromagnesite, and the sulfide tochilinite, each of which is known in the meteorite collection (Rubin, 1996). Although a full discussion of the petrogenesis and classification of hydrated minerals is beyond the scope of this paper, we note that formation of hydrated minerals, particularly clay minerals, occurs rapidly and easily in environments where anhydrous rock and water are together.
  2. Snellings, R.; Mertens G.; Elsen J. (2012). "Supplementary cementitious materials". Reviews in Mineralogy and Geochemistry. 74 (1): 211–278. Bibcode:2012RvMG...74..211S. doi:10.2138/rmg.2012.74.6.
  3. 1 2 mindat.org (6 February 2023). "Tochilinite". mindat.org. Retrieved 16 February 2023.
  4. Handbook of mineralogy (2005). "Tochilinite" (PDF). handbookofmineralogy.org. Retrieved 16 February 2023.
  5. Valleriite on Mindat.org
  6. Handbook of Mineralogy