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Cohenite Mineral Data
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General Cohenite Information
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 Chemical Formula: |
(Fe,Ni,Co)3C |
| Composition: |
Molecular Weight = 183.04 gm |
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Iron 54.92 % Fe |
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Cobalt 9.66 % Co |
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Nickel 28.86 % Ni |
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Carbon 6.56 % C |
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______ |
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100.00 % |
| Empirical Formula: |
Fe0+1.8Ni0.9Co0.3C |
| Environment: |
In iron meteorites, also in terrestrial iron, in mafic rocks chemically reduced from the assimilation of graphite. |
| IMA Status: |
Valid Species (Pre-IMA) 1889 |
| Locality: |
Common in iron meteorites. Link to MinDat.org Location Data. |
| Name Origin: |
Named for Emil Wilhelm Cohen (1842-1905), Professor of Mineralogy, University of Greifswald, Greifswald, Germany. |
| Synonym: |
ICSD 16593 |
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PDF 35-772 |
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Cohenite Image |
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Images:
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Cohenite
Comments: Bluish gray, metallic iridescent crystals of cohenite on matrix.
Location: Kopeisk, Chelyabinsk Oblast', Urals Region, Russia.
Scale: 2.3 mm.
© Thomas Witzke / Abraxas-Verlag |
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Images:
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Cohenite Crystallography
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| Axial Ratios: |
a:b:c =0.8913:1:1.3288 |
| Cell Dimensions: |
a = 4.518, b = 5.069, c = 6.736, Z = 4; V = 154.27 Den(Calc)= 7.88 |
| Crystal System: |
Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pbnm |
| X Ray Diffraction: |
By Intensity(I/Io): 2.01(1), 2.06(0.7), 2.38(0.65), |
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Physical Properties of Cohenite
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| Cleavage: |
{???} Good, {???} Good, {???} Good |
| Color: |
Yellowish white. |
| Density: |
7.2 - 7.65, Average = 7.42 |
| Diaphaneity: |
Opaque |
| Fracture: |
Brittle - Generally displayed by glasses and most non-metallic minerals. |
| Hardness: |
5.5-6 - Knife Blade-Orthoclase |
| Luster: |
Metallic |
| Magnetism: |
Strongly magnetic |
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Optical Properties of Cohenite
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| RL Color: |
Tin-white. |
| Reflectivity |
Standardized Intensity (100%) Reflection Spectra of Cohenite in Air
| λ |
R1 |
R2 |
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∑ R1(λ) |
∑ R2(λ) |
| 400 nm |
51.80 |
54.70 |
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| 420 nm |
52.60 |
55.20 |
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| 440 nm |
53.20 |
55.70 |
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| 460 nm |
53.80 |
56.20 |
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| 480 nm |
54.40 |
56.70 |
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| 500 nm |
55.00 |
57.10 |
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| 520 nm |
55.60 |
57.70 |
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| 540 nm |
56.20 |
58.20 |
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| 560 nm |
56.80 |
58.80 |
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| 580 nm |
57.40 |
59.30 |
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| 600 nm |
58.00 |
60.00 |
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| 620 nm |
58.70 |
60.60 |
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| 640 nm |
59.30 |
61.30 |
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| 660 nm |
60.00 |
62.00 |
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| 680 nm |
60.80 |
62.80 |
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| 700 nm |
61.60 |
63.60 |
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Calculated Relative Intensity Colors of Cohenite in Air
Relative
Intensity |
0% |
20% |
40% |
60% |
80% |
100% |
120% |
140% |
160% |
170% |
| R1 |
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| R2 |
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Calculated Properties of Cohenite
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| Electron Density: |
Bulk Density (Electron Density)=7.41 gm/cc
note: Specific Gravity of Cohenite =7.88 gm/cc.
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| Fermion Index: |
Fermion Index = 0.01
Boson Index = 0.99 |
| Photoelectric: |
PECohenite = 32.09 barns/electron
U=PECohenite x rElectron Density= 237.86 barns/cc.
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| Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Cohenite is Not Radioactive |
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Cohenite Classification
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| Dana Class: |
01.01.16.01 (01)Native Elements |
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(01.01)with metallic elements other than the platinum group |
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(01.01.16)Dana Group |
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01.01.16.01 Cohenite (Fe,Ni,Co)3C Pbnm 2/m 2/m 2/m |
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01.01.16.02 Haxonite (Fe,Ni)23C6 F m3m 4/m 3 2/m |
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01.01.16.03 Isovite! (Cr,Fe)23C6 F m3m 4/m 3 2/m |
| Strunz Class: |
01.BA.05 01 - ELEMENTS (Metals and intermetallic alloys; metalloids and nonmetals; carbides, silicides, nitrides, phosphides) |
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01.B - Metallic Carbides, Silicides, Nitrides and Phosphides |
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01.BA -Carbides |
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01.BA.05 Cohenite (Fe,Ni,Co)3C Pbnm 2/m 2/m 2/m |
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Other Cohenite 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 Cohenite :
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 Cohenite Specimen Label here :
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Cohenite
(Fe,Ni,Co)3C
Dana No: 01.01.16.01 Strunz No: 01.BA.05
Locality:
Notes:
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