Editing Dolomite (mineral) (section)

==Formation==
Modern dolomite formation has been found to occur under [[Hypoxia (environmental)|anaerobic]] conditions in [[Supersaturation|supersaturated]] saline [[lagoon]]s such as those at the [[Rio de Janeiro]] coast of [[Brazil]], namely, Lagoa Vermelha and Brejo do Espinho. There are many other localities where modern dolomite forms, notably along [[sabkha]]s in the [[Persian Gulf]],<ref name=":1">{{Cite journal|date=2017-08-01|title=Microbially catalyzed dolomite formation: From near-surface to burial|url=https://www.sciencedirect.com/science/article/abs/pii/S0012825217301885|journal=Earth-Science Reviews|language=en|volume=171|pages=558–582|doi=10.1016/j.earscirev.2017.06.015|issn=0012-8252|last1=Petrash|first1=Daniel A.|last2=Bialik|first2=Or M.|last3=Bontognali|first3=Tomaso R.R.|last4=Vasconcelos|first4=Crisógono|last5=Roberts|first5=Jennifer A.|last6=McKenzie|first6=Judith A.|last7=Konhauser|first7=Kurt O.|bibcode=2017ESRv..171..558P}}</ref> but also in sedimentary basins bearing gas hydrates<ref>{{Cite journal|last1=Snyder|first1=Glen T.|last2=Matsumoto|first2=Ryo|last3=Suzuki|first3=Yohey|last4=Kouduka|first4=Mariko|last5=Kakizaki|first5=Yoshihiro|last6=Zhang|first6=Naizhong|last7=Tomaru|first7=Hitoshi|last8=Sano|first8=Yuji|last9=Takahata|first9=Naoto|last10=Tanaka|first10=Kentaro|last11=Bowden|first11=Stephen A.|date=2020-02-05|title=Evidence in the Japan Sea of microdolomite mineralization within gas hydrate microbiomes|journal=Scientific Reports|language=en|volume=10|issue=1|pages=1876|doi=10.1038/s41598-020-58723-y|pmid=32024862|issn=2045-2322|pmc=7002378|bibcode=2020NatSR..10.1876S}}</ref> and hypersaline lakes.<ref>{{Cite journal|date=1990-05-01|title=Lacustrine dolomite—an overview of modern, Holocene, and Pleistocene occurrences|url=https://www.sciencedirect.com/science/article/abs/pii/001282529090004F|journal=Earth-Science Reviews|language=en|volume=27|issue=3|pages=221–263|doi=10.1016/0012-8252(90)90004-F|issn=0012-8252|last1=Last|first1=William M.|bibcode=1990ESRv...27..221L}}</ref> It is often thought that dolomite nucleates with the help of [[sulfate-reducing bacteria]] (e.g. ''Desulfovibrio brasiliensis''),<ref>{{cite journal|author1=Vasconcelos C. |author2=McKenzie J. A. |author3=Bernasconi S. |author4=Grujic D. |author5=Tien A. J. |year=1995|title=Microbial mediation as a possible mechanism for natural dolomite formation at low temperatures|journal= Nature |volume=337|issue=6546|pages= 220–222|doi=10.1038/377220a0|bibcode = 1995Natur.377..220V |s2cid=4371495 }}</ref> but other [[microbial metabolism]]s have been also found to mediate in dolomite formation.<ref name=":1" /> In general, low-temperature dolomite may occur in natural supersaturated environments rich in [[Extracellular polymeric substance|extracellular polymeric substances (EPS)]] and microbial cell surfaces.<ref name=":1" /> This is likely result from complexation of  both magnesium and calcium by [[carboxylic acid]]s comprising EPS.<ref>{{cite journal|author1=Roberts, J. A. |author2=Kenward, P. A. |author3=Fowle, D. A. |author4=Goldstein, R. H. |author5=Gonzalez, L. A. |author6= Moore, D. S. |name-list-style=amp |year=1980|title=Surface chemistry allows for abiotic precipitation of dolomite at low temperature |journal= Proceedings of the National Academy of Sciences of the United States of America |volume=110|issue=36|pages=14540–5|doi=10.1073/pnas.1305403110|pmid=23964124|pmc=3767548|bibcode=2013PNAS..11014540R|doi-access=free }}</ref>

Vast deposits of dolomite are present in the geological record, but the mineral is relatively rare in modern environments. Reproducible, inorganic low-temperature syntheses of dolomite are yet to be performed. Usually, the initial inorganic precipitation of a metastable "precursor" (such as magnesium calcite) can easily be achieved. The precursor phase will theoretically change gradually into a more stable phase (such as partially ordered dolomite) during periodical intervals of dissolution and re-precipitation. The general principle governing the course of this irreversible [[geochemistry|geochemical]] reaction has been coined "breaking [[Ostwald's step rule]]".<ref>Deelman, J.C. (1999): [http://www.jcdeelman.demon.nl/dolomite/files/NeuesJahrbuchMineral.pdf "Low-temperature nucleation of magnesite and dolomite"] {{webarchive|url=https://web.archive.org/web/20080409113312/http://www.jcdeelman.demon.nl/dolomite/files/NeuesJahrbuchMineral.pdf |date=2008-04-09 }}, ''Neues Jahrbuch für Mineralogie'', Monatshefte, pp. 289–302.</ref>  High diagenetic temperatures, such as those of groundwater flowing along deeply rooted fault systems affecting some sedimentary successions or deeply buried limestone rocks allocate [[dolomitization]].<ref>{{Cite journal|date=2000-11-01|title=Dolomite: occurrence, evolution and economically important associations|url=https://www.sciencedirect.com/science/article/abs/pii/S0012825200000222|journal=Earth-Science Reviews|language=en|volume=52|issue=1–3|pages=1–81|doi=10.1016/S0012-8252(00)00022-2|issn=0012-8252|last1=Warren|first1=J.|bibcode=2000ESRv...52....1W}}</ref>  But the mineral is also volumetrically important in some [[Neogene]] platforms never subjected to elevated temperatures. Under such conditions of [[diagenesis]] the long-term activity of the [[deep biosphere]] could play a key role in dolomitization, since diagenetic fluids of contrasting composition are mixed as a response to [[Milankovitch cycles]].<ref>{{Cite journal|last1=Petrash|first1=Daniel A.|last2=Bialik|first2=Or M.|last3=Staudigel|first3=Philip T.|last4=Konhauser|first4=Kurt O.|last5=Budd|first5=David A.|title=Biogeochemical reappraisal of the freshwater–seawater mixing-zone diagenetic model|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/sed.12849|journal=Sedimentology|year=2021|volume=68|issue=5|pages=1797–1830|language=en|doi=10.1111/sed.12849|s2cid=234012426|issn=1365-3091}}</ref>

A recent biotic synthetic experiment claims to have precipitated ordered dolomite when [[anoxygenic photosynthesis]] proceeds in the presence of manganese(II).<ref>{{Cite journal|last1=Daye|first1=Mirna|last2=Higgins|first2=John|last3=Bosak|first3=Tanja|date=2019-06-01|title=Formation of ordered dolomite in anaerobic photosynthetic biofilms|url=https://pubs.geoscienceworld.org/gsa/geology/article-abstract/47/6/509/569965/Formation-of-ordered-dolomite-in-anaerobic|journal=Geology|language=en|volume=47|issue=6|pages=509–512|doi=10.1130/G45821.1|bibcode=2019Geo....47..509D|issn=0091-7613|hdl=1721.1/126802|s2cid=146426700|hdl-access=free}}</ref> A still perplexing example of an organogenic origin is that of the reported formation of dolomite in the [[urinary bladder]] of a [[Dalmatian (dog)|Dalmatian]] dog, possibly as the result of an illness or infection.<ref>{{cite journal|author=Mansfield, Charles F. |year=1980|bibcode=1980GeCoA..44..829M|title=A urolith of biogenic dolomite – another clue in the dolomite mystery|journal=Geochimica et Cosmochimica Acta|volume=44|issue=6|pages=829–839|doi=10.1016/0016-7037(80)90264-1}}</ref>