{{Short description|Very rare mineral}} {{Infobox mineral | name = Akdalaite | boxwidth = | boxbgcolor = | image = | imagesize = | alt = | caption = | struct image = | struct caption = | struct imagesize = | struct2 image = | struct2 caption = | struct2 imagesize= | SMILES = | Jmol = | category = | formula = {{chem2|5Al2O3*H2O|auto=1}} | IMAsymbol = Akd | molweight = | strunz = | dana = | system = | class = | symmetry = | unit cell = | color = White, pale greenish yellow in thin section | colour = | habit = | twinning = | cleavage = | fracture = Irregular/uneven | tenacity = | toughness = | mohs = 7–7.5 | luster = Vitreous | streak = White | diaphaneity = Translucent | gravity = 3.68 | density = | polish = | opticalprop = | refractive = | birefringence = | pleochroism = | 2V = | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | Curie temp = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | prop1 = | prop1text = | references = | var1 = | var1text = | var2 = | var2text = | var3 = | var3text = | var4 = | var4text = | var5 = | var5text = | var6 = | var6text = }} thumb | right | White vitreous crystal aggregates of the extremely rare Al mineral akdalaite from the TL (Solnechnoye Mine, Kara-Oba, Karazhal, Ulytau Region, Kazakhstan) and only one of 6 known localities worldwide. Ex Vandenbroucke Museum collection from Waregem, Belgium. '''Akdalaite''' (IMA symbol: Akd<ref>{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA-CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3|pages=291–320|doi=10.1180/mgm.2021.43|bibcode=2021MinM...85..291W|s2cid=235729616|doi-access=free}}</ref>) is a very rare mineral found in Kazakhstan and has the formula {{chem2|5Al2O3*H2O|auto=1}}.<ref>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}}</ref> It was formerly believed to be {{chem2|4Al2O3*H2O}}. 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.<ref>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}}</ref>
==References== {{reflist}}
== External links == {{Wiktionary}} * [http://www.mindat.org/min-69.html Fact sheet] from mindat.org * [http://www.webmineral.com/data/Akdalaite.shtml Fact sheet] from [http://webmineral.com webmineral.com]
Category:Aluminium minerals Category:Oxide minerals Category:Monohydrate minerals Category:Hexagonal minerals Category:Minerals described in 1969
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