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Iwakiite Mineral Data
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General Iwakiite Information
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 Chemical Formula: |
Mn++(Fe+++,Mn+++)2O4 |
| Composition: |
Molecular Weight = 229.99 gm |
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Manganese 40.61 % Mn 30.84 % MnO / 24.03 % Mn2O3 |
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Iron 31.57 % Fe 40.61 % FeO |
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Oxygen 27.83 % O |
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______ ______ |
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100.00 % 95.48 % = TOTAL OXIDE |
| Empirical Formula: |
Mn2+Fe2+1.3Mn3+0.7O4 |
| Environment: |
Regionally metamorphosed bedded manganese deposit. |
| IMA Status: |
Approved IMA 1979 |
| Locality: |
Gozaisho mine, Iwaki, Fukushima Prefecture, Japan. Link to MinDat.org Location Data. |
| Name Origin: |
Named for the locality. |
| Name Pronunciation: |
Iwakiite  |
| Synonym: |
ICSD 76612 |
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PDF 38-430 |
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alpha vrendenbergite |
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vrendenbergite alpha |
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Iwakiite Image |
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Images:
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Iwakiite Crystallography
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| Axial Ratios: |
a:c = 1:1.00246 |
| Cell Dimensions: |
a = 8.519, c = 8.54, Z = 8; V = 619.78 Den(Calc)= 4.93 |
| Crystal System: |
Tetragonal - Ditetragonal Dipyramidal H-M Symbol (4/m 2/m 2/m) Space Group: P 41/nnm |
| X Ray Diffraction: |
By Intensity(I/Io): 2.57(1), 1.506(0.4), 3.016(0.4), |
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Physical Properties of Iwakiite
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| Cleavage: |
None |
| Color: |
Greenish black. |
| Density: |
4.85 |
| Diaphaneity: |
Opaque |
| Habit: |
Aggregates - Made of numerous individual crystals or clusters. |
| Habit: |
Anhedral Grains - Granular minerals without the expression of crystal shapes |
| Hardness: |
6-6.5 - Orthoclase-Pyrite |
| Luster: |
Metallic |
| Magnetism: |
Strongly magnetic |
| Streak: |
black |
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Optical Properties of Iwakiite
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| Optical Data: |
Uniaxial (?). |
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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
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| RL Anisotrophism: |
Moderate, yellowish to brownish gray. |
| RL Color: |
Light olive gray. |
| Reflectivity |
Standardized Intensity (100%) Reflection Spectra of Iwakiite in Air
| λ |
R1 |
R2 |
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∑ R1(λ) |
∑ R2(λ) |
| 420 nm |
20.00 |
19.40 |
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| 440 nm |
19.90 |
19.30 |
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| 460 nm |
20.30 |
19.50 |
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| 480 nm |
20.40 |
19.60 |
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| 500 nm |
20.80 |
19.80 |
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| 520 nm |
21.20 |
20.10 |
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| 540 nm |
21.40 |
20.30 |
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| 560 nm |
21.30 |
20.40 |
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| 580 nm |
21.20 |
20.10 |
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| 600 nm |
21.00 |
20.00 |
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| 620 nm |
20.90 |
19.70 |
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| 640 nm |
20.50 |
19.60 |
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| 660 nm |
20.40 |
19.20 |
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| 680 nm |
20.20 |
19.10 |
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Calculated Relative Intensity Colors of Iwakiite in Air
Relative
Intensity |
0% |
50% |
100% |
150% |
200% |
250% |
300% |
350% |
400% |
450% |
| R1 |
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| R2 |
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Calculated Properties of Iwakiite
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| Electron Density: |
Bulk Density (Electron Density)=4.64 gm/cc
note: Specific Gravity of Iwakiite =4.93 gm/cc.
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| Fermion Index: |
Fermion Index = 0.006825684
Boson Index = 0.993174316 |
| Photoelectric: |
PEIwakiite = 20.39 barns/electron
U=PEIwakiite x rElectron Density= 94.68 barns/cc.
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| Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Iwakiite is Not Radioactive |
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Iwakiite Classification
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| Dana Class: |
07.02.06.02 (07)Multiple Oxides |
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(07.02)(A+ B++)2 X4 Spinel group |
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(07.02.06)Dana Group |
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07.02.06.01 Kusachiite CuBi2O4 P 4/ncc 4/m 2/m 2/m |
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07.02.06.02 Iwakiite Mn(Fe,Mn)2O4 P 41/nnm 4/m 2/m 2/m |
| Strunz Class: |
04.BB.10 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate |
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04.B - Metal:Oxygen = 3:4 and similar |
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04.BB -With only medium-sized cations |
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04.BB.10 Hausmannite MnMn2O4 I 41/amd 4/m 2/m 2/m |
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04.BB.10 Iwakiite Mn(Fe,Mn)2O4 P 41/nnm 4/m 2/m 2/m |
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04.BB.10 Hydrohetaerolite Zn2Mn4O8•(H2O) I 41/amd 4/m 2/m 2/m |
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04.BB.10 Hetaerolite ZnMn2O4 I 41/amd 4/m 2/m 2/m |
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Other Iwakiite Information
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| References: |
NAME( AntBidBlaNic3) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic3) |
| 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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Print or Cut-and-Paste your Iwakiite Specimen Label here :
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Iwakiite
Mn++(Fe+++,Mn+++)2O4
Dana No: 07.02.06.02 Strunz No: 04.BB.10
Locality:
Notes:
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