SUPPORT US. Covid-19 has significantly affected our fundraising. Please help!
Log InRegister
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreContact UsAdvertise on Mindat
Donate to MindatCorporate SponsorshipSponsor a PageSponsored PagesMindat AdvertisersAdvertise on Mindat
Learning CenterWhat is a mineral?The most common minerals on earthInformation for EducatorsMindat ArticlesThe ElementsBooks & Magazines
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
Mining CompaniesStatisticsUsersMineral MuseumsMineral Shows & EventsThe Mindat DirectoryDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryMineral Photography


This page is currently not sponsored. Click here to sponsor this page.
Hide all sections | Show all sections

About AkdalaiteHide

formerly here as 5Al2O3.H2O
White, pale greenish yellow in thin section
7 - 7½
Specific Gravity:
Crystal System:
For the Kazakh name, Akdala, for the type locality.
Isostructural with:
In the structure there are oxygen planes with ABACA sequence (Yamaguchi et al., 1964). In the ab initio model proposed by Demichelis et al. (2008) there are 8 Al atoms located in the octahedral cavities and 2 Al atoms in the tetrahedral ones; two types of irregular AlO6 edge-sharing octahedra; AlO4 vertices-sharing tetrahedra. There are 2 sheets of first-type (a) octahedra, and two sheets with second-type (b) octahedra and tetrahedra (c).

Recently (2019) proved to be the Al analogue of ferrihydrite.

Classification of AkdalaiteHide

Approval Year:

4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
F : Hydroxides (without V or U)
L : Hydroxides with H2O +- (OH); sheets of edge-sharing octahedra

3 : A2X3

7 : Oxides and Hydroxides
6 : Oxides of Al

Physical Properties of AkdalaiteHide

vitreous to porcelaneous
White, pale greenish yellow in thin section
7 - 7½ on Mohs scale
None Observed
3.68 g/cm3 (Measured)    3.673 g/cm3 (Calculated)

Optical Data of AkdalaiteHide

Uniaxial (-)
RI values:
nω = 1.747 nε = 1.741
Max Birefringence:
δ = 0.006
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
Surface Relief:

Chemical Properties of AkdalaiteHide


formerly here as 5Al2O3.H2O
IMA Formula:
(Al2O3)5 · H2O

Crystallography of AkdalaiteHide

Crystal System:
Cell Parameters:
a = 12.87 Å, c = 14.97 Å
a:c = 1 : 1.163
Unit Cell V:
2,147.38 ų (Calculated from Unit Cell)
As hexagonal crystals, to 0.8 mm, tabular to equant; in lenslike aggregates.
Possible space groups: P6122, P61

Crystal StructureHide

Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
CIF File    Best | x | y | z | a | b | c
Stop | Start
Console Off | On | Grey | Yellow
IDSpeciesReferenceLinkYearLocalityPressure (GPa)Temp (K)
0012146AkdalaiteYamaguchi G, Okumiya M, Ono S (1969) Refinement of the structure of tohdite 5Al2O3*H2O Bulletin of the Chemical Society of Japan 42 2247-22491969synthetic0293
0013283AkdalaiteDemichelis R, Noel Y, Zicovich-Wilson C M, Roetti C, Valenzano L, Dovesi R (2008) Ab-initio quantum mechanical study of akdalaite (5Al2O3*H2O): Structure and vibrational spectrum, Journal of Physics: Conference Series 117 012013-0120132008Theoretical structure0293
0013284AkdalaiteDemichelis R, Noel Y, Zicovich-Wilson C M, Roetti C, Valenzano L, Dovesi R (2008) Ab-initio quantum mechanical study of akdalaite (5Al2O3*H2O): Structure and vibrational spectrum, Journal of Physics: Conference Series 117 012013-0120132008Theoretical structure0293
0013285AkdalaiteDemichelis R, Noel Y, Zicovich-Wilson C M, Roetti C, Valenzano L, Dovesi R (2008) Ab-initio quantum mechanical study of akdalaite (5Al2O3*H2O): Structure and vibrational spectrum, Journal of Physics: Conference Series 117 012013-0120132008Theoretical structure0293
CIF Raw Data - click here to close

X-Ray Powder DiffractionHide

Powder Diffraction Data:
0.9931 Å(9)
1.393 Å(10)
1.418 Å(10)
2.11 Å(10)
2.32 Å(8)
2.35 Å(9)
2.494 Å(9)
Material from type locality

Type Occurrence of AkdalaiteHide

General Appearance of Type Material:
lenslike aggregates and tabular to equant hexagonal crystals to 0.1 mm
Place of Conservation of Type Material:
A. E. Fersman Mineralogical Museum, Academy of Sciences, Moscow, Russia
Geological Setting of Type Material:
veinlets cutting amesite-fluorite-muscovite rock and fluorite-magnetite-diopside-vesuvianite skarn
Associated Minerals at Type Locality:

Synonyms of AkdalaiteHide

Other Language Names for AkdalaiteHide


Common AssociatesHide

Associated Minerals Based on Photo Data:
1 photo of Akdalaite associated with AluminiumAl

Related Minerals - Nickel-Strunz GroupingHide

4.FL.TrébeurdeniteFe2+2Fe3+4O2(OH)10CO3·3H2OTrig. 3m (3 2/m) : R3m
4.FL.05WoodalliteMg6Cr2(OH)16Cl2 · 4H2OTrig. 3m (3 2/m) : R3m
4.FL.05IowaiteMg6Fe3+2(OH)16Cl2 · 4H2OTrig. 3m (3 2/m) : R3m
4.FL.05JamboriteNi2+1-xCo3+x(OH)2-x(SO4)x · nH2OTrig. 3m (3 2/m) : R3m
4.FL.05MeixneriteMg6Al2(OH)16(OH)2 · 4H2OTrig. 3m (3 2/m) : R3m
4.FL.05MuskoxiteMg7Fe4O13 · 10H2OTrig. 3m (3 2/m)
4.FL.05FougèriteFe2+4Fe3+2(OH)12[CO3]·3H2OTrig. 3m (3 2/m) : R3m
4.FL.10HydrocalumiteCa4Al2(OH)12(Cl,CO3,OH)2 · 4H2OMon. 2 : P21
4.FL.15KuzeliteCa4Al2(OH)12[SO4] · 6H2OTrig.
4.FL.20AuroriteMn2+Mn4+3O7 · 3H2OTrig. 3 : R3
4.FL.20ChalcophaniteZnMn4+3O7 · 3H2OTrig. 3 : R3
4.FL.20ErnienickeliteNiMn3O7 · 3H2OTrig. 3 : R3
4.FL.20Jianshuiite(Mg,Mn,Ca)Mn3O7 · 3H2OTrig. 3 : R3
4.FL.25WoodruffiteZn2+x/2(Mn4+1-xMn3+x)O2·yH2OMon. 2/m : B2/m
4.FL.30Asbolane(Ni,Co)2-xMn4+(O,OH)4 · nH2OHex.
4.FL.35BuseriteNa4Mn14O27 · 21H2O
4.FL.40Ranciéite(Ca,Mn2+)0.2(Mn4+,Mn3+)O2 · 0.6H2OTrig. 3 : P3
4.FL.40Takanelite(Mn,Ca)Mn4O9 · H2OHex.
4.FL.45Birnessite(Na,Ca)0.5(Mn4+,Mn3+)2O4 · 1.5H2OMon. 2/m : B2/m
4.FL.55CianciulliiteMn(Mg,Mn)2Zn2(OH)10 · 2-4H2OMon. 2/m : B2/m
4.FL.60JenseniteCu3[TeO6] · 2H2OMon. 2/m : P21/m
4.FL.65LeisingiteCu2MgTe6+O6 · 6H2OTrig. 3 : P3
4.FL.75CafetiteCaTi2O5 · H2OMon. 2/m : P21/b
4.FL.85DeloryiteCu4(UO2)(MoO4)2(OH)6Mon. 2/m : B2/m

Related Minerals - Dana Grouping (8th Ed.)Hide

Related Minerals - Hey's Chemical Index of Minerals GroupingHide

7.6.1CorundumAl2O3Trig. 3m (3 2/m) : R3c
7.6.2BöhmiteAlO(OH)Orth. mmm (2/m 2/m 2/m)
7.6.2DiasporeAlO(OH)Orth. mmm (2/m 2/m 2/m)
7.6.4GibbsiteAl(OH)3Mon. 2/m
7.6.5BayeriteAl(OH)3Mon. 2/m : P21/m
7.6.6NordstranditeAl(OH)3Tric. 1 : P1

Other InformationHide

Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

References for AkdalaiteHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Yamaguchi, G., Yanagida, H., Shuitiro, O. (1964) New alumina hydrate, "tohdite" (5Al2O3·H2O). Bulletin of the Chemical Society of Japan: 37: 752-754.
Shpanov, E.P., Sidorenko, G.A., Stolyarova, T.I. (1970) Akdalaite, a new hydrous modification of alumina. Zapiski Vserossiyskogo Mineralogicheskogo Obshchestva: 99: 333-339. [in Russian]
Fleischer, M. (1971) American Mineralogist: 56: 635. [abstract]
Anthony, J.W., Bideaux, R.A., Bladh, K.W., Nichols, M.C. (1997) Handbook of Mineralogy, Vol. 3: Halides, Hydroxides, Oxides. Mineral Data Publishing (Tucson, AZ), 8.
Demichelis, R., Noel, Y., Zicovich-Wilson, C.M., Roetti, C., Valenzano, L., Dovesi, R. (2008) Ab-initio quantum mechanical study of akdalaite (5Al2O3·H2O): Structure and vibrational spectrum. Journal of Physics: Conference Series: 117: 012013.
Parise, J.B., Xia, B., Simonson, J.W., Woerner, W.R., Plonka, A.M., Phillips, B.L., Ehm, L. (2019): Structural Chemistry of Akdalaite, Al10O14(OH)2, the Isostructural Aluminum Analogue of Ferrihydrite. Crystals: 9(5): 246;;

Internet Links for AkdalaiteHide

Localities for AkdalaiteHide

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. - Good crystals or important locality for species. - World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (eg from pseudomorphs.)

All localities listed without proper references should be considered as questionable.
  • Queensland
    • Cook Shire
      • Cape York Peninsula
Tilley, D.B., Eggleton, R.A. (1996) The Natural Occurrence of Eta-Alumina (η-Al2O3) in Bauxite Clays and Clay Minerals, 44(5), 658-664.
  • Gobustan District
    • Caspian Sea
Novgorodova M.I., MamedovYu.G. Lithology and Mineral Resources, 1996,N4, p.339-349
  • Akmola Region
Hwang, S. L., Shen, P., Chu, H. T., & Yui, T. F. (2006). A new occurrence and new data on akdalaite, a retrograde mineral from UHP Whiteschist, Kokchetav Massif, Northern Kazakhstan. International Geology Review, 48(8), 754-764.
  • Karaganda Region
    • Karazhal
      • Betpakdala Desert (Bet-Pak-Dal Desert)
        • Kara-Oba W deposit
Pekov, I. (1998) Minerals First discovered on the territory of the former Soviet Union 369p. Ocean Pictures, Moscow; Fleischer M (1971) New mineral names. American Mineralogist 56, 631-640
South Africa
  • Northern Cape
Zhou, B., Sherriff, B. L., Taulelle, F., & Wu, G. (2003). Nuclear magnetic resonance study of Al: Si and F: OH order in zunyite. The Canadian Mineralogist, 41(4), 891-903.
  • Idaho
    • Latah Co.
Hwang, S. L., Shen, P., Chu, H. T., Yui, T. F., & Iizuka, Y. (2015). Origin of rutile needles in star garnet and implications for interpretation of inclusion textures in ultrahigh‐pressure metamorphic rocks. Journal of Metamorphic Geology, 33(3), 249-272.
Mineral and/or Locality is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Public Relations by Blytheweigh.
Copyright © and the Hudson Institute of Mineralogy 1993-2020, except where stated. Most political location boundaries are © OpenStreetMap contributors. relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: August 7, 2020 05:33:27 Page generated: July 24, 2020 14:15:56
Go to top of page