Chemistry:Hazenite

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Short description: Phosphate mineral
Hazenite
General
CategoryPhosphate mineral
Struvite group
Formula
(repeating unit)
KNaMg
2
(PO
4
)
2
 · 14 H
2
O
Strunz classification8.CH.40
Dana classification40.01.01.03
Crystal systemOrthorhombic
Crystal classDipyramidal (mmm)
H–M Symbol: (2/m 2/m 2/m)
Space groupPmnb
Unit cella = 6.9349, b = 25.1737
c = 11.2189 [Å]; Z = 4
Identification
Formula mass276.331 g/mol
ColorColorless
Crystal habitRadiating elongated tabular or prismatic clusters or single bladed tabular crystals
Cleavage{001} Good
TenacityBrittle
Mohs scale hardness2 – 2.5
|re|er}}Vitreous
StreakWhite
DiaphaneityTransparent
Specific gravity1.91
Optical propertiesBiaxial (+)
Refractive indexnα =1.494(1), nβ = 1.498(1), nγ = 1.503(1)
2V angle41°
DispersionStrong r < v
SolubilityIn water
References[1][2][3]

Hazenite is a hydrous phosphate mineral with chemical formula of KNaMg
2
(PO
4
)
2
 · 14 H
2
O
, therefore a hydrous alkali magnesium phosphate. It is a member of the struvite group.[3]

It was first described for an occurrence adjacent to Mono Lake, California , and named after Robert M. Hazen of the Carnegie Institute.[5] It was approved as a new mineral on February 28, 2008 by the Commission on New Minerals of the International Mineralogical Association.

It occurs as crystal clusters associated with decomposed cyanobacteria remnants on calcite or aragonite.[3] It is precipitated by microbes when the lake has been dry for so long that phosphorus levels build up, poisoning the microbes. They dispose of the excess phosphorus by excreting hazenite crystals.[6] The crystals disappear when it rains or the lake level rises.[7]

References

  1. "Hazenite". Hudson Institute of Mineralogy. http://www.mindat.org/min-38992.html. Retrieved 15 May 2018. 
  2. Yang, H.; Sun, H. J.; Downs, R. T. (21 March 2011). "Hazenite, KNaMg2(PO4)2{middle dot}14H2O, a new biologically related phosphate mineral, from Mono Lake, California, U.S.A.". American Mineralogist 96 (4): 675–681. doi:10.2138/am.2011.3668. 
  3. 3.0 3.1 3.2 Barthelmy, Dave. "Hazenite Mineral Data". http://webmineral.com/data/Hazenite.shtml#.WvsYUS-G9SM. Retrieved 15 May 2018. 
  4. Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine 85 (3): 291–320. doi:10.1180/mgm.2021.43. Bibcode2021MinM...85..291W. 
  5. "New mineral to be named "Hazenite" after Robert Hazen" (in en). Geophysical Laboratory (Carnegie Institution of Washington). https://legacy.gl.ciw.edu/news/personnel_awards_and_honors/new_mineral_be_named_hazenite_after_robert_hazen. Retrieved 15 May 2018. 
  6. Hazen told the Los Angeles Times , "They're basically microbial poop. People tell me, 'Hazenite happens.'" (Netburn, Deborah (13 February 2016). "Way beyond diamonds: A look at some of the rarest minerals in the world". Los Angeles Times. http://www.latimes.com/science/sciencenow/la-sci-sn-rare-minerals-20160213-story.html. Retrieved 15 May 2018. )
  7. Wernick, Adam (21 May 2017). "Evidence that we are in the Age of Man: Scientists catalog more human-made minerals" (in en). 90.5 WESA (World Media Foundation). http://wesa.fm/post/evidence-we-are-age-man-scientists-catalog-more-human-made-minerals#stream/0. Retrieved 15 May 2018.