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About IowaiteHide

Flag of Iowa, USA
Mg6Fe3+2(OH)16Cl2 · 4H2O
bluish green
Specific Gravity:
Crystal System:
For the state of the type locality.
Hydrotalcite Group. Chemically similar to kuliginite, which however is anhydrous.

Bluish green, becoming pale green with a rusty red tint on exposure to air (alteration to pyroaurite).

Classification of IowaiteHide

First Published:

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

4 : Miscellaneous

8 : Halides - Fluorides, Chlorides, Bromides and Iodides; also Fluoborates and Fluosilicates
11 : Halides of Fe and Ni

Physical Properties of IowaiteHide

bluish green
1½ on Mohs scale
Perfect basal cleavage
2.11(2) g/cm3 (Measured)    

Optical Data of IowaiteHide

Uniaxial (-)
RI values:
nω = 1.543 - 1.561 nε = 1.533 - 1.543
Max Birefringence:
δ = 0.010 - 0.018
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
Surface Relief:

Chemical Properties of IowaiteHide

Mg6Fe3+2(OH)16Cl2 · 4H2O

Crystallography of IowaiteHide

Crystal System:
Class (H-M):
3m (3 2/m) - Hexagonal Scalenohedral
Space Group:
Cell Parameters:
a = 3.119(5) Å, c = 24.25(2) Å
a:c = 1 : 7.775
Unit Cell V:
204.30 ų (Calculated from Unit Cell)
Call parameters from powder diffraction data

Geological EnvironmentHide

Paragenetic Mode(s):

Type Occurrence of IowaiteHide

General Appearance of Type Material:
Platy crystals 2-3mm in size
Place of Conservation of Type Material:
National Museum of Natural History, Washington, D.C., USA, 121706.
Geological Setting of Type Material:
Altered serpentinite in precambrian basement
Kohls, D.W., Rodda,, J.L. (1967) Iowaite, a new hydrous magnesium hydroxide-ferric oxychloride from the Precambrian of Iowa. American Mineralogist: 52: 1261-1271.

Synonyms of IowaiteHide

Other Language Names for IowaiteHide


Varieties of IowaiteHide

Chromian IowaiteIowaite with significant replacement of Fe3+ by Cr3+ transitive to Woodallite.

Relationship of Iowaite to other SpeciesHide

Other Members of this group:
DesautelsiteMg6Mn3+2(OH)16[CO3] · 4H2OTrig. 3m (3 2/m)
DroninoiteNi6Fe2+3(OH)16Cl2 · 4H2OTrig. 3m (3 2/m) : R3m
HydrotalciteMg6Al2(CO3)(OH)16 · 4H2OTrig. 3m (3 2/m) : R3m
Hydrotalcite-3RMg6Al2(CO3)(OH)16 · 4H2OTrig. 3m (3 2/m) : R3m
MeixneriteMg6Al2(OH)16(OH)2 · 4H2OTrig. 3m (3 2/m) : R3m
PyroauriteMg6Fe3+2(OH)16[CO3] · 4H2OTrig. 3m (3 2/m) : R3m
ReevesiteNi6Fe3+2(OH)16(CO3) · 4H2OTrig.
StichtiteMg6Cr3+2(OH)16[CO3] · 4H2OTrig. 3m (3 2/m) : R3m
TakoviteNi6Al2(OH)16[CO3] · 4H2OTrig. 3m (3 2/m) : R3m
UM1998-10-CO:CoHNiNi6Co2(CO3)(OH)16 · 4H2O
WoodalliteMg6Cr2(OH)16Cl2 · 4H2OTrig. 3m (3 2/m) : R3m

Common AssociatesHide

Associated Minerals Based on Photo Data:
8 photos of Iowaite associated with MagnetiteFe2+Fe3+2O4
7 photos of Iowaite associated with Valleriite(Fe2+,Cu)4(Mg,Al)3S4(OH,O)6
6 photos of Iowaite associated with CalciteCaCO3
4 photos of Iowaite associated with FluorapatiteCa5(PO4)3F
2 photos of Iowaite associated with LizarditeMg3(Si2O5)(OH)4
1 photo of Iowaite associated with GypsumCaSO4 · 2H2O
1 photo of Iowaite associated with BruciteMg(OH)2
1 photo of Iowaite associated with Pentlandite(FexNiy)Σ9S8
1 photo of Iowaite associated with WoodalliteMg6Cr2(OH)16Cl2 · 4H2O
1 photo of Iowaite associated with MuscoviteKAl2(AlSi3O10)(OH)2

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.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

Related Minerals - Hey's Chemical Index of Minerals GroupingHide

8.11.2HydromolysiteFeCl3 · 6H2O
8.11.3RokühniteFeCl2 · 2H2OMon.
8.11.5ErythrosideriteK2[Fe3+Cl5(H2O)]Orth. mmm (2/m 2/m 2/m) : Pnma
8.11.6RinneiteK3Na[FeCl6]Trig. 3m (3 2/m) : R3c
8.11.7Kremersite(NH4,K)2[Fe3+Cl5(H2O)]Orth. mmm (2/m 2/m 2/m)
8.11.9NickelbischofiteNiCl2 · 6H2OMon.
8.11.10Lawrencite(Fe2+,Ni)Cl2Trig. 3m (3 2/m) : R3m

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 IowaiteHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Kohls, D.W., Rodda,, J.L. (1967) Iowaite, a new hydrous magnesium hydroxide-ferric oxychloride from the Precambrian of Iowa. American Mineralogist: 52: 1261-1271.
Allmann, R., Donnay, J.D.H. (1969) About the structure of iowaite. American Mineralogist: 54: 296-299.
Braithwaite, R.S.W., Dunn, P.J., Pritchard, R.G., Paar, W.H. (1994) Iowaite, a re-investigation. Mineralogical Magazine: 58: 79-85.
Jambor, J.L., Roberts, A.C., Vanko, D.A. (1994) New mineral names. American Mineralogist: 79: 1009-1014.
Mills, S.J., Christy, A.G., Genin, J.-M.R., Kameda, T., Colombo, F. (2012) Nomenclature of the hydrotalcite supergroup: natural layered double hydroxides. Mineralogical Magazine: 76: 1289-1336.

Internet Links for IowaiteHide

Localities for IowaiteHide

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.
Atlantic Ocean
Plas, A. A. (1997). Petrologic and stable isotope constraints on fluid-rock interaction, serpentinization and alternation of oceanic ultramafic rocks (Doctoral dissertation, ETH Zurich).
  • Walvis Ridge
Moll, M., Paulick, H., Suhr, G., & Bach, W. (2007). Data report: microprobe analyses of primary phases (olivine, pyroxene, and spinel) and alteration products (serpentine, iowaite, talc, magnetite, and sulfides) in Holes 1268A, 1272A, and 1274A. In Proceedings of the Ocean Drilling Program, Scientific Results (Vol. 209, pp. 1-13). College Station, TX: Ocean Drilling Program.
  • Western Australia
    • Kalgoorlie-Boulder Shire
      • Kanowna Goldfield
Barnes, S. J., Wells, M. A., & Verrall, M. R. (2009). Effects of magmatic processes, serpentinization, and talc-carbonate alteration on sulfide mineralogy and ore textures in the Black Swan disseminated nickel sulfide deposit, Yilgarn Craton. Economic Geology, 104(4), 539-562.
    • Wiluna Shire
      • Lake Way Station
Disseminated and Massive Nickel Sulphide Deposits,Honeymoon Well Complex, Western Australia; M Gole and M Woodhouse, Journal of the Virtual Explorer; ISSN 1441-8142 Vol 1 paper 2, 2000
Grguric, B.A., Seat, Z., Karpuzov, A.A., Simonov, O.N. (2013) The West Jordan deposit, a newly-discovered Type 2 dunite-hosted nickel sulphide system in the northern Agnew-Wiluna Belt, Western Australia. Ore Geology Reviews, Vol. 51, pg. 79-92
Wilson, S.A., Harrison, A.L., Dipple, G.M., Power, I.M., Barker, S.L.L., Ulrich, M.K., Fallon, S.J., Raudsepp, M., Southam, G. (2014) Offsetting of CO2 emissions by air capture in mine tailings at the Mount Keith Nickel Mine, Western Australia: Rates, controls and prospects for carbon neutral mining. International Journal of Greenhouse Gas Control 25 121-140
[AmMin 87:182]
  • Manitoba
    • Thompson Nickel Belt
Franchuk, Anatoliy, Peter C. Lightfoot, and Daniel J. Kontak. "High tenor Ni–PGE sulfide mineralization in the South Manasan ultramafic intrusion, Paleoproterozoic Thompson Nickel Belt, Manitoba, Canada." Ore Geology Reviews 72 (2016): 434-458.
  • Ontario
    • Kenora District
      • Ring of Fire
        • BMA527861 Area
Jordan E. Laarman (2014) A Detailed Metallogenic Study of the McFaulds Lake Chromite Deposits, Northern Ontario, The University of Western Ontario,London, Ontario, PhD Thesis
Jordan E. Laarman (2014) A Detailed Metallogenic Study of the McFaulds Lake Chromite Deposits, Northern Ontario, The University of Western Ontario,London, Ontario, PhD Thesis
  • Québec
    • Estrie
      • Les Sources RCM
        • Asbestos
HORVÁTH, L., PFENNINGER-HORVÁTH, E. and SPERTINI, F. (2013) The Jeffrey mine, Asbestos, Québec, Canada: A mineralogical review. Mineralogical Record, 44, 375-417.
  • Inner Mongolia
    • Xilingol League (Xilinguole Prefecture)
      • West Ujimqin Banner (Xiwuzhumuqin Co.)
Zhu, H., Jingsui, Y., Robinson, P. T., Yongwang, Z., Fahui, X., Zhao, L., ... & Wei, X. (2015). The discovery of diamonds in chromitites of the Hegenshan ophiolite, Inner Mongolia, China. Acta Geologica Sinica‐English Edition, 89(2), 341-350.
  • New Caledonia
    • Southern Province
      • Mont-Dore Commune
Monnin, C., Chavagnac, V., Boulart, C., Ménez, B., Gérard, M., Gérard, E., ... & Guentas-Dombrowski, L. (2014). Fluid chemistry of the low temperature hyperalkaline hydrothermal system of Prony Bay (New Caledonia). Biogeosciences, 11(20), 5687-5706.
  • Al Batinah North Governorate
Chavagnac, V., Ceuleneer, G., Monnin, C., Lansac, B., Hoareau, G., & Boulart, C. (2013). Mineralogical assemblages forming at hyperalkaline warm springs hosted on ultramafic rocks: a case study of Oman and Ligurian ophiolites. Geochemistry, Geophysics, Geosystems, 14(7), 2474-2495.
Pacific Ocean
  • East Pacific Rise
Plas, A. A. (1997). Petrologic and stable isotope constraints on fluid-rock interaction, serpentinization and alternation of oceanic ultramafic rocks (Doctoral dissertation, ETH Zurich).
  • Mariana forearc
Heling, D., A. Schwarz (1992) Iowaite in Serpentinite Muds at Sites 778, 779, 780 and 784: a possible cause for the low chlorinity of pore waters: Proceedings of the Ocean Drilling Program, Scientific Results: 125.
Wheat, C.G., Fryer, P., Fisher, A.T., Hulme, S., Jannasch, H., Mottl, M.J., Becker, K. (2008) Borehole observations of fluid flow from South Chamorro Seamount, an active serpentinite mud volcano in the Mariana forearc. Earth and Planetary Science Letters, 267(3-4), 401-409.
  • Silesian Voivodeship
    • Wodzisław Co.
      • Radlin
Łukasz Kruszewski (2012) Unique chloride assemblage of exhalative origin from burning coal-mining dump in Radlin (Rybnik Coal Area, S Poland). Mineralogical Society of Poland Special Papers 40
    • Zawiercie Co.
Koszowska E., Salata D. 2001: Minerals of the hydrotalcite group in metasomatically altered carbonate rocks from Zawiercie, S Poland. Mineralogia Polonica, vol. 32, no 1, 69-84
  • Altai Republic
    • Ust-Koksinsky District
Igor V. Pekov data
  • Irkutsk Oblast
    • Zheleznogorsk (Korshunikha)
Mazurov, M.P., Grishina, S.N., Istomin, V.E., and Titov, A.T. (2007): Geology of Ore Deposits 49(4), 271-284.; Mazurov et al (2007) Geology of Ore Deposits, 49, 271–284.
  • Krasnoyarsk Krai
    • Taymyrskiy Autonomous Okrug
      • Taimyr Peninsula
        • Putoran Plateau
          • Noril'sk
            • Talnakh Cu-Ni Deposit
Handbook of Mineralogy; Evseev, A. A. (1973) Siberia's Crystals and Symmetry in the Distribution of Occurences of Minerals. World of Stone 1:11-20
  • Sakha Republic (Yakutia)
    • Mirninsky District
      • Daldyn
Pavel M. Kartashov data; Mikhailenko, D.S., Korsakov, A.V., Rashchenko, S.V., Seryotkin, Y.V., Belakovskiy, D.I., Golovin, A.V. (2018): Kuliginite, a new hydroxychloride mineral from the Udachnaya kimberlite pipe, Yakutia: Implications for low-temperature hydrothermal alteration of the kimberlites. American Mineralogist, 103: 1435–1444; Rezvukhin, D.I.; Alifirova, T.A.; Golovin, A.V.; Korsakov, A.V. (2020) A Plethora of Epigenetic Minerals Reveals a Multistage Metasomatic Overprint of a Mantle Orthopyroxenite from the Udachnaya Kimberlite. Minerals 10, 264.
South Africa
  • Limpopo
    • Phalaborwa
      • Loolekop
Minerals of South Africa; Braithwaite, R. S. W., Dunn, P. J., Pritchard, R. G., & Parr, W. H. (1994). Iowaite, a reinvestigation. Mineralogical Magazine, 58(390), 77-86.; Gliddon, J. (1996) Minerals of the Palabora open pit. British Micromount Society 43:2-7
  • Andalusia
    • Almería
      • Fiñana
Evans, B. W., & Cowan, D. S. (2012). A Melt origin for spinifex-textured metaperidotite in the Cerro del Almirez massif, southern Spain. American Journal of Science, 312(9), 967-993.
  • Iowa
    • Sioux Co.
American Mineralogist: 52: 1261-1271.
  • Tashkent
    • Piskent District
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