Wairakite

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Kent G. Budge (talk | contribs) at 22:19, 31 December 2020. The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Wairakite
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
Lustervitreous, 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 Alfred Steiner in 1955.[3][4] The first finds were in hydrothermally altered rhyolitic tuffs, ignimbrites and volcaniclastic rocks.[4] 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.[5]

References

  1. ^ Mindat
  2. ^ Mineralienatlas
  3. ^ Szostak, Rosemarie (1992), Handbook of molecular sieves, Springer, p. 482, ISBN 0-442-31899-5
  4. ^ a b Steiner, Alfred (1955), "Wairakite, the calcium analogue of analcime, a new zeolite mineral" (PDF), Mineralogy Magazine, 30: 691–698, retrieved 2011-09-08
  5. ^ Liou, J. G., "Synthesis and stability relations of wairakite, CaAl2 Si4 O12·2H2O", Contributions to Mineralogy and Petrology, 27 (4): 259–282, Bibcode:1970CoMP...27..259L, doi:10.1007/BF00389814