Mineralogy Database

Iwakiite Mineral Data

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General Iwakiite Information

Help on Chemical  Formula: Chemical Formula: Mn++(Fe+++,Mn+++)2O4
Help on Composition: Composition: Molecular Weight = 229.99 gm
   Manganese  40.61 %  Mn   30.84 % MnO / 24.03 % Mn2O3
   Iron       31.57 %  Fe   40.61 % FeO
   Oxygen     27.83 %  O
             ______        ______ 
             100.00 %       95.48 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Mn2+Fe2+1.3Mn3+0.7O4
Help on Environment: Environment: Regionally metamorphosed bedded manganese deposit.
Help on IMA Status: IMA Status: Approved IMA 1979
Help on Locality: Locality: Gozaisho mine, Iwaki, Fukushima Prefecture, Japan. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for the locality.
Help on Name Pronunciation: Name Pronunciation: Iwakiite Say IWAKIITE
Help on Synonym: Synonym: ICSD 76612
  PDF 38-430
  alpha vrendenbergite
  vrendenbergite alpha

Iwakiite Image

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Comments: Back fine-grained granular iwakiite in pink rhodonite.
Location: Gazaisho Mine, Iwaki, Fukushima, Japan. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Iwakiite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:1.00246
Help on Cell Dimensions: Cell Dimensions: a = 8.519, c = 8.54, Z = 8; V = 619.78 Den(Calc)= 4.93
Help on Crystal System: Crystal System: Tetragonal - Ditetragonal Dipyramidal H-M Symbol (4/m 2/m 2/m) Space Group: P 41/nnm
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.57(1), 1.506(0.4), 3.016(0.4),

Physical Properties of Iwakiite

Help on Cleavage: Cleavage: None
Help on Color: Color: Greenish black.
Help on Density: Density: 4.85
Help on Diaphaneity: Diaphaneity: Opaque
Help on Habit: Habit: Aggregates - Made of numerous individual crystals or clusters.
Help on Habit: Habit: Anhedral Grains - Granular minerals without the expression of crystal shapes
Help on Hardness: Hardness: 6-6.5 - Orthoclase-Pyrite
Help on Luster: Luster: Metallic
Help on Magnetism: Magnetism: Strongly magnetic
Help on Streak: Streak: black

Optical Properties of Iwakiite

Help on Optical Data: Optical Data: Uniaxial (?).
  NCalc= 2.03 - from Gladstone-Dale relationship (KC = 0.2094) where Ncalc=Dcalc*KC+1
NCalc= 2.02 - from Gladstone-Dale relationship (KC = 0.2094) where Ncalc=Dmeas*KC+1
Help on RL Anisotrophism: RL Anisotrophism: Moderate, yellowish to brownish gray.
Help on RL Color: RL Color: Light olive gray.
Help on Reflectivity Reflectivity
Standardized Intensity (100%) Reflection Spectra of Iwakiite in Air
λ R1 R2  ∑ R1(λ)   ∑ R2(λ) 
 420 nm   20.00   19.40 
 440 nm   19.90   19.30 
 460 nm   20.30   19.50 
 480 nm   20.40   19.60 
 500 nm   20.80   19.80 
 520 nm   21.20   20.10 
 540 nm   21.40   20.30 
 560 nm   21.30   20.40 
 580 nm   21.20   20.10 
 600 nm   21.00   20.00 
 620 nm   20.90   19.70 
 640 nm   20.50   19.60 
 660 nm   20.40   19.20 
 680 nm   20.20   19.10 
Calculated Relative Intensity Colors of Iwakiite in Air
   0%   50% 100% 150% 200% 250% 300% 350% 400% 450%

Calculated Properties of Iwakiite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=4.64 gm/cc
note: Specific Gravity of Iwakiite =4.93 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.006825684
Boson Index = 0.993174316
Help on Photoelectric: Photoelectric: PEIwakiite = 20.39 barns/electron
U=PEIwakiite x rElectron Density= 94.68 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Iwakiite is Not Radioactive

Iwakiite Classification

Help on  Dana Class: Dana Class: (07)Multiple Oxides
  (07.02)(A+ B++)2 X4 Spinel group
  (07.02.06)Dana Group Kusachiite CuBi2O4 P 4/ncc 4/m 2/m 2/m Iwakiite Mn(Fe,Mn)2O4 P 41/nnm 4/m 2/m 2/m
Help on  Strunz Class: Strunz Class: 04.BB.10 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate
  04.B - Metal:Oxygen = 3:4 and similar
  04.BB -With only medium-sized cations
04.BB.10 Hausmannite MnMn2O4 I 41/amd 4/m 2/m 2/m
04.BB.10 Iwakiite Mn(Fe,Mn)2O4 P 41/nnm 4/m 2/m 2/m
04.BB.10 Hydrohetaerolite Zn2Mn4O8•(H2O) I 41/amd 4/m 2/m 2/m
04.BB.10 Hetaerolite ZnMn2O4 I 41/amd 4/m 2/m 2/m

Other Iwakiite Information

Help on References: References: NAME( AntBidBlaNic3) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic3)
Help on See Also: See Also: Links to other databases for Iwakiite :
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 - MinDAT
10 - Mineralienatlas (Deutsch)
11 - Online Mineral Museum
12 - QUT Mineral Atlas
13 - Ruff.Info

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Dana No: Strunz No: 04.BB.10





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