Chemistry:Akdalaite

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Short description: Very rare mineral
Akdalaite
General
CategoryMineral
Formula
(repeating unit)
5Al
2
O
3
 · H2O
Identification
ColorWhite, pale greenish yellow in thin section
FractureIrregular/uneven
Mohs scale hardness7–7.5
|re|er}}Vitreous
StreakWhite
DiaphaneityTranslucent
Specific gravity3.68

Akdalaite (IMA symbol: Akd[1]) is a very rare mineral found in Kazakhstan and has the formula 5Al
2
O
3
 · H2O
.[2] It was formerly believed to be 4Al
2
O
3
 · H
2
O
. It is therefore the same as tohdite an artificially produced phase. Studies on the crystal structure and spectra indicate that this is an aluminium oxide hydroxide.[3]

References

  1. Warr, L.N. (2021). "IMA-CNMNC approved mineral symbols". Mineralogical Magazine 85 (3): 291–320. doi:10.1180/mgm.2021.43. Bibcode2021MinM...85..291W. 
  2. A New Occurrence and New Data on Akdalaite, a Retrograde Mineral from UHP Whiteschist, Kokchetav Massif, Northern Kazakhstan, Shyh-Lung Hwang, Pouyan Shen, Hao-Tsu Chu, Tzen-Fu Yui, International Geology Review, 48, 8, 2006, 754-764, doi:10.2747/0020-6814.48.8.754
  3. Ab-initio quantum mechanical study of akdalaite (5Al2O3· H2O): structure and vibrational spectrum, Demichelis, R.; Noel, Y.; Zicovich-Wilson, C. M.; Roetti, C.; Valenzano, L.; Dovesi, R., Journal of Physics: Conference Series, Volume 117, Issue 1, pp. 012013 (2008)., doi:10.1088/1742-6596/117/1/012013

External links