Chemistry:Wairakite

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Wairakite
Wairakite.jpg
Wairakite from Azerbaijan
General
CategoryZeolite minerals
Formula
(repeating unit)
Ca8(Al16Si32O96)•16H2O
Strunz classification9.GB.05
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupI2/a
Unit cella = 13.69 Å, b = 13.64 Å
c = 13.56 Å; β = 90.51°; Z = 8
Identification
Colorcolorless to white
|re|er}}vitreous, dull
Streakwhite
Diaphaneitytransparent, translucent
References[1][2]

Wairakite is a zeolite mineral with an analcime structure but containing a calcium ion. The chemical composition is Ca8(Al16Si32O96)•16H2O. It is named for the location of its discovery in Wairakei, North Island, New Zealand, by Czechoslovakian mineralogist Alfred Steiner in 1955.[4][5] The first finds were in hydrothermally altered rhyolitic tuffs, ignimbrites and volcaniclastic rocks.[5] The mineral has since been found in metamorphic rocks and in geothermal areas. It was most likely first successfully synthesized in a laboratory in 1970.[6]

References

  1. Mindat
  2. Mineralienatlas
  3. Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine 85 (3): 291–320. doi:10.1180/mgm.2021.43. Bibcode2021MinM...85..291W. 
  4. Szostak, Rosemarie (1992), Handbook of molecular sieves, Springer, p. 482, ISBN 0-442-31899-5, https://books.google.com/books?id=tSXDrpyqQc8C&pg=PA482 
  5. 5.0 5.1 Steiner, Alfred (1955), "Wairakite, the calcium analogue of analcime, a new zeolite mineral", Mineralogical Magazine and Journal of the Mineralogical Society 30 (230): 691–698, doi:10.1180/minmag.1955.030.230.02, Bibcode1955MinM...30..691S, http://rruff.info/uploads/MM30_691.pdf, retrieved 2011-09-08 
  6. Liou, J. G. (1970), "Synthesis and stability relations of wairakite, CaAl2 Si4 O12·2H2O", Contributions to Mineralogy and Petrology 27 (4): 259–282, doi:10.1007/BF00389814, Bibcode1970CoMP...27..259L