Wairakite
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]
| Wairakite | |
|---|---|
 Wairakite from Azerbaijan | |
| General | |
| Category | Zeolite minerals |
| Formula (repeating unit) | Ca8(Al16Si32O96)•16H2O |
| Strunz classification | 9.GB.05 |
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) (same H-M symbol) |
| Space group | I2/a |
| Unit cell | a = 13.69 Å, b = 13.64 Å c = 13.56 Å; β = 90.51°; Z = 8 |
| Identification | |
| Color | colorless to white |
| Luster | vitreous, dull |
| Streak | white |
| Diaphaneity | transparent, translucent |
| References | [1][2] |
References
- Mindat
- Mineralienatlas
- Szostak, Rosemarie (1992), Handbook of molecular sieves, Springer, p. 482, ISBN 0-442-31899-5
- Steiner, Alfred (1955), "Wairakite, the calcium analogue of analcime, a new zeolite mineral" (PDF), Mineralogy Magazine, 30: 691–698, retrieved 2011-09-08
- 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
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