Iowaite Mineral Data
General Iowaite Information
Chemical Formula:
Mg4Fe+++(OH)8OCl•2-4(H2O)
Composition:
Molecular Weight = 394.62 gm
Magnesium 24.64 % Mg 40.85 % MgO
Iron 14.15 % Fe 20.23 % Fe2 O3
Hydrogen 3.58 % H 31.96 % H2 O
Chlorine 8.98 % Cl 8.98 % Cl
- %
Cl -2.03 % -O=Cl2
Oxygen 48.65 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Mg4 Fe3+ (OH)8 OCl•3(H2 O)
Environment:
Veinlets in serpentinite.
IMA Status:
Approved IMA 1967
Locality:
Sioux County, Iowa. Link to MinDat.org Location Data.
Name Origin:
Named for the locality.
Name Pronunciation:
Iowaite
Synonym:
ICSD 15202
PDF 20-500
Iowaite Image
Images:
Iowaite
Comments: Floater crystal of iowaite.
Location: Palabora Mine, Transvaal, South Africa.
Scale: Crystal size 1.2 cm.
© John Veevaert
Iowaite Crystallography
Axial Ratios:
a:c = 1:7.86149
Cell Dimensions:
a = 3.119, c = 24.52, Z = 0.6; V = 206.58 Den(Calc)= 1.90
Crystal System:
Trigonal - Hexagonal Scalenohedral H-M Symbol (3 2/m) Space Group: R 3 m
X Ray Diffraction:
By Intensity(I/Io ): 8.109(1), 4.047(0.4), 2.363(0.27),
Physical Properties of Iowaite
Cleavage:
{0001} Perfect
Color:
Bluish green, Greenish white, Honey yellow.
Density:
2.09 - 2.11, Average = 2.09
Diaphaneity:
Transparent
Habit:
Platy - Sheet forms (e.g. micas).
Hardness:
1.5 - Between Talc and Gypsum
Luster:
Greasy (Oily)
Streak:
white
Optical Properties of Iowaite
Gladstone-Dale:
CI meas = 0.081 (Poor) - where the CI = (1-KPDmeas /KC ) CI calc = -0.015 (Superior) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.2868,KPDmeas = 0.2595,KC = 0.2825 Ncalc = 1.54 - 1.6
Optical Data:
Uniaxial (-), e=1.533-1.543, w=1.543-1.561, bire=0.0100-0.0180.
Calculated Properties of Iowaite
Electron Density:
Bulk Density (Electron Density)=1.94 gm/cc note: Specific Gravity of Iowaite =1.90 gm/cc.
Fermion Index:
Fermion Index = 0.02 Boson Index = 0.98
Photoelectric:
PEIowaite = 5.25 barns/electronU=PEIowaite x r Electron Density= 10.17 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Iowaite is Not Radioactive
Iowaite Classification
Dana Class:
06.04.05.01 (06) Hydroxides and Oxides Containing Hydroxyl
(06.04) containing multiple cations
(06.04.05) Dana Group
06.04.05.01 Iowaite Mg4Fe(OH)8OCl•2-4(H2O) R 3 m 3 2/m
06.04.05.02 Woodallite ! Mg6Cr2(OH)16Cl2•4(H2O) R 3 m 3 2/m
Strunz Class:
04.FL.05 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate
04.F - Hydroxides (without V or U)
04.FL -Hydroxides with H2O � (OH); sheets of edge-sharing octahedra
04.FL.05 Akdalaite 5(Al2O3)•(H2O) P 63 mc 6mm
04.FL.05 Meixnerite Mg6Al2(OH)18•4(H2O) R 3 m 3 2/m
04.FL.05 Jamborite (Ni,Ni,Fe)(OH)2(OH,S,(H2O)) Unk Hex
04.FL.05 Iowaite Mg4Fe(OH)8OCl•2-4(H2O) R 3 m 3 2/m
04.FL.05 Muskoxite Mg7Fe4O13•10(H2O) Unk (pseudo HEX-R) Trig
04.FL.05 Woodallite ! Mg6Cr2(OH)16Cl2•4(H2O) R 3 m 3 2/m
Other Iowaite Information
References:
NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
See Also:
Links to other databases for Iowaite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info
15 - WWW-MINCRYST
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Print or Cut-and-Paste your Iowaite Specimen Label here :
Iowaite
Mg4Fe+++(OH)8OCl•2-4(H2O)
Dana No: 06.04.05.01 Strunz No: 04.FL.05
Locality:
Notes:
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