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{{Short description|Calcium carbonate mineral}}
'''Vaterite''' ([[calcium|Ca]][[carbon|C]][[oxygen|O]]<sub>3</sub>) is a mineral, a [[polymorphism (materials science)|polymorph]] of [[calcium carbonate]]. It was named after the German mineralogist Heinrich Vater. It is also known as mu-calcium carbonate (&mu;-CaCO<sub>3</sub>) and has a [[JCPDS]] number of 13-192. Vaterite, like aragonite, is a metastable phase of calcium carbonate at ambient conditions at the surface of the earth. As it is less stable than either calcite or aragonite, vaterite has a higher [[solubility]] than either of these phases. Therefore, once vaterite is exposed to [[water]], it converts to [[calcite]] (at low temperature) or [[aragonite]] (at high temperature: ~60°C). However, vaterite does occur naturally in [[mineral spring]]s, organic tissue, [[gallstone]]s, and urinary calculi. In those circumstances, some impurities ([[metal]] ions or organic matter) may stabilize the vaterite and prevent its transformation into [[calcite]] or [[aragonite]]. Vaterite is usually colorless, its shape is spherical, and its diameter is small, ranging from 0.05 to 5 &mu;m.
{{Infobox mineral
| name = Vaterite
| boxwidth =
| boxbgcolor =
| image = Vaterite2-San Vito, Monte Somma, Italy.tif
| imagesize =
| alt =
| caption = Vaterite from San Vito quarry, San Vito, Monte Somma, Somma-Vesuvius Complex, Italy
| category = [[Carbonate minerals]]
| formula = CaCO<sub>3</sub>
| IMAsymbol = Vtr<ref>{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3|pages=291–320|doi=10.1180/mgm.2021.43|bibcode=2021MinM...85..291W|s2cid=235729616|doi-access=free}}</ref>
| molweight =
| strunz = 5.AB.20
| dana =
| system = [[Hexagonal crystal system|Hexagonal]]
| class = Dihexagonal dipyramidal (6mmm) <br/>[[H-M symbol]]: (6/m 2/m 2/m)
| symmetry = P6<sub>3</sub>/mmc {P6<sub>3</sub>/m 2/m 2/c}
| unit cell = a = 4.13, c = 8.49&nbsp;[Å]; Z&nbsp;=&nbsp;6
| color = Colorless
| colour =
| habit = Fine fibrous crystals, typically less than 0.1 mm, in spherulitic aggregates.
| twinning =
| cleavage =
| fracture = Irregular to uneven, splintery
| tenacity = Brittle
| mohs = 3
| luster = Sub-vitreous, waxy
| streak =
| diaphaneity = Transparent to semi-transparent
| gravity = 2.54
| density =
| polish =
| opticalprop = Uniaxial (+)
| refractive = n<sub>ω</sub> = 1.550 n<sub>ε</sub> = 1.650
| birefringence = δ = 0.100
| pleochroism =
| 2V =
| dispersion =
| extinction =
| length fast/slow =
| fluorescence =
| absorption =
| melt =
| fusibility =
| diagnostic =
| solubility =
| impurities =
| alteration =
| other =
| prop1 =
| prop1text =
| references = <ref name=Mindat>[http://www.mindat.org/min-4161.html Mindat.org]</ref><ref name=HBM>[http://rruff.geo.arizona.edu/doclib/hom/vaterite.pdf Handbook of Mineralogy]</ref><ref name=Webmin>[http://webmineral.com/data/Vaterite.shtml Webmineral data]</ref>
}}


'''Vaterite''' is a mineral, a [[polymorphism (materials science)|polymorph]] of [[calcium carbonate]] ([[calcium|Ca]][[carbon|C]][[oxygen|O]]<sub>3</sub>). It was named after the German mineralogist [[Heinrich Vater]]. It is also known as mu-[[calcium carbonate]] (μ-CaCO<sub>3</sub>). Vaterite belongs to the [[hexagonal crystal system]], whereas [[calcite]] is [[trigonal]] and [[aragonite]] is [[orthorhombic]].
Vaterite can be produced as the first mineral deposits repairing natural or experimentally induced shell damage in some aragonite-shelled molluscs (e.g., gastropods). Subsequent shell deposition occurs as aragonite.


Vaterite, like aragonite, is a [[metastable]] phase of calcium carbonate at ambient conditions at the surface of the Earth. As it is less stable than either calcite, the most stable polymorph,<ref>{{cite journal|last1=Ni|first1=Ming|last2=Ratner|first2=Buddy D.|title=Differentiation of Calcium Carbonate Polymorphs by Surface Analysis Techniques – An XPS and TOF-SIMS study|journal=Surface and Interface Analysis|volume=40|issue=10|pages=1356-1361|doi=10.1002/sia.2904|year=2008|pmc=4096336|pmid=25031482}}</ref> or aragonite, vaterite has a higher [[solubility]] than either of these phases. Therefore, once vaterite is exposed to [[water]], it converts to calcite (at low temperature) or aragonite (at high temperature: ~60&nbsp;°C). At 37&nbsp;°C for example a solution-mediated transition from vaterite to calcite occurs, where the vaterite dissolves and subsequently precipitates as calcite assisted by an [[Ostwald ripening]] process.<ref name=Zhou2010>{{cite journal | first1= Gen-Tao |last1=Zhou | first2=Qi-Zhi |last2=Yao | first3=Sheng-Quan |last3=Fu | first4=Ye-Bin |last4=Guan | url= http://eurjmin.geoscienceworld.org/content/22/2/259| date=2010|title =Controlled crystallization of unstable vaterite with distinct morphologies and their polymorphic transition to stable calcite| doi= 10.1127/0935-1221/2009/0022-2008 | journal= European Journal of Mineralogy|volume=22 |issue=2 |pages=259–269 |bibcode=2010EJMin..22..259Z }}</ref>
Vaterite belongs to the [[hexagonal crystal system]], whereas calcite is [[trigonal]] and aragonite is [[orthorhombic]].

However, vaterite does occur naturally in [[mineral spring]]s, organic tissue, [[gallstone]]s, [[urinary calculi]] and plants. In those circumstances, some impurities ([[metal]] ions or organic matter) may stabilize the vaterite and prevent its transformation into calcite or aragonite. Vaterite is usually colorless.

Vaterite can be produced as the first mineral deposits repairing natural or experimentally-induced shell damage in some aragonite-shelled mollusks (e.g. gastropods). Subsequent shell deposition occurs as aragonite. In 2018, vaterite was identified as a constituent of a deposit formed on the leaves of ''[[Saxifraga]]'' at [[Cambridge University Botanic Garden]].<ref>{{cite news|title=Incredible discovery at Cambridge's Botanic Garden that could transform treatment of cancer|url=https://www.cambridge-news.co.uk/news/cambridge-news/botanic-garden-cambridge-vaterite-cancer-14399149|date=12 Mar 2018|archiveurl=https://web.archive.org/web/20180312131958/https://www.cambridge-news.co.uk/news/cambridge-news/botanic-garden-cambridge-vaterite-cancer-14399149|archivedate=2018-03-12|newspaper=Cambridge News|author=Chris Elliott}}</ref><ref>{{cite web|title=Rare mineral discovered in plants for first time|url=https://www.sciencedaily.com/releases/2018/03/180305101631.htm|date=5 Mar 2018|website=Science Daily}}</ref>

Vaterite has a [[JCPDS]] number of {{not a typo|13-192}}.
[[File:Vaterite.png|thumb|Crystal structure of vaterite]]

[[File:Vaterite1-San Vito, Monte Somma, Italy.tif|thumb|left|Vaterites of the locality San Vito (Monte Somma, [[Italy]]) are microcrystalline with largest crystals below 2 mm size. This vaterite is [[epitactic]] after aragonite. The crystal contains triplet of aragonite inside of it. On its termination twin seams of aragonite triplet are well visible.]]


==See also==
==See also==
Line 12: Line 74:


==References==
==References==
{{Reflist}}
* [http://webmineral.com/data/Vaterite.shtml Webmineral data]
* [http://www.mindat.org/min-4161.html Mindat.org]


[[Category:Calcium minerals]]
[[Category:Calcium minerals]]
[[Category:Carbonate minerals]]
[[Category:Carbonate minerals]]
[[Category:Hexagonal minerals]]
{{Carbonate-mineral-stub}}
[[Category:Minerals in space group 194]]
[[Category:Polymorphism (materials science)]]



{{Mineral-stub}}
[[de:Vaterit]]
[[fr:Vatérite]]
[[it:Vaterite]]
[[hu:Vaterit]]
[[ru:Фатерит]]

Latest revision as of 16:39, 19 November 2024

Vaterite
Vaterite from San Vito quarry, San Vito, Monte Somma, Somma-Vesuvius Complex, Italy
General
CategoryCarbonate minerals
Formula
(repeating unit)		CaCO3
IMA symbolVtr[1]
Strunz classification5.AB.20
Crystal systemHexagonal
Crystal classDihexagonal dipyramidal (6mmm)
H-M symbol: (6/m 2/m 2/m)
Space groupP63/mmc {P63/m 2/m 2/c}
Unit cella = 4.13, c = 8.49 [Å]; Z = 6
Identification
ColorColorless
Crystal habitFine fibrous crystals, typically less than 0.1 mm, in spherulitic aggregates.
FractureIrregular to uneven, splintery
TenacityBrittle
Mohs scale hardness3
LusterSub-vitreous, waxy
DiaphaneityTransparent to semi-transparent
Specific gravity2.54
Optical propertiesUniaxial (+)
Refractive indexnω = 1.550 nε = 1.650
Birefringenceδ = 0.100
References[2][3][4]

Vaterite is a mineral, a polymorph of calcium carbonate (CaCO3). It was named after the German mineralogist Heinrich Vater. It is also known as mu-calcium carbonate (μ-CaCO3). Vaterite belongs to the hexagonal crystal system, whereas calcite is trigonal and aragonite is orthorhombic.

Vaterite, like aragonite, is a metastable phase of calcium carbonate at ambient conditions at the surface of the Earth. As it is less stable than either calcite, the most stable polymorph,[5] or aragonite, vaterite has a higher solubility than either of these phases. Therefore, once vaterite is exposed to water, it converts to calcite (at low temperature) or aragonite (at high temperature: ~60 °C). At 37 °C for example a solution-mediated transition from vaterite to calcite occurs, where the vaterite dissolves and subsequently precipitates as calcite assisted by an Ostwald ripening process.[6]

However, vaterite does occur naturally in mineral springs, organic tissue, gallstones, urinary calculi and plants. In those circumstances, some impurities (metal ions or organic matter) may stabilize the vaterite and prevent its transformation into calcite or aragonite. Vaterite is usually colorless.

Vaterite can be produced as the first mineral deposits repairing natural or experimentally-induced shell damage in some aragonite-shelled mollusks (e.g. gastropods). Subsequent shell deposition occurs as aragonite. In 2018, vaterite was identified as a constituent of a deposit formed on the leaves of Saxifraga at Cambridge University Botanic Garden.[7][8]

Vaterite has a JCPDS number of 13-192.

Crystal structure of vaterite
Vaterites of the locality San Vito (Monte Somma, Italy) are microcrystalline with largest crystals below 2 mm size. This vaterite is epitactic after aragonite. The crystal contains triplet of aragonite inside of it. On its termination twin seams of aragonite triplet are well visible.

See also

[edit]

References

[edit]
  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ Mindat.org
  3. ^ Handbook of Mineralogy
  4. ^ Webmineral data
  5. ^ Ni, Ming; Ratner, Buddy D. (2008). "Differentiation of Calcium Carbonate Polymorphs by Surface Analysis Techniques – An XPS and TOF-SIMS study". Surface and Interface Analysis. 40 (10): 1356–1361. doi:10.1002/sia.2904. PMC 4096336. PMID 25031482.
  6. ^ Zhou, Gen-Tao; Yao, Qi-Zhi; Fu, Sheng-Quan; Guan, Ye-Bin (2010). "Controlled crystallization of unstable vaterite with distinct morphologies and their polymorphic transition to stable calcite". European Journal of Mineralogy. 22 (2): 259–269. Bibcode:2010EJMin..22..259Z. doi:10.1127/0935-1221/2009/0022-2008.
  7. ^ Chris Elliott (12 Mar 2018). "Incredible discovery at Cambridge's Botanic Garden that could transform treatment of cancer". Cambridge News. Archived from the original on 2018-03-12.
  8. ^ "Rare mineral discovered in plants for first time". Science Daily. 5 Mar 2018.


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