Mineralogy Database

Cochromite Mineral Data

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General Cochromite Information

Help on Chemical  Formula: Chemical Formula: (Co,Ni,Fe++)(Cr,Al)2O4
Help on Composition: Composition: Molecular Weight = 207.97 gm
   Magnesium   1.17 %  Mg    1.94 % MgO
   Aluminum    5.19 %  Al    9.81 % Al2O3
   Chromium   35.00 %  Cr   51.16 % Cr2O3
   Iron        8.06 %  Fe    6.91 % FeO /  3.84 % Fe2O3
   Cobalt     14.17 %  Co   18.01 % CoO
   Nickel      5.64 %  Ni    7.18 % NiO
   Oxygen     30.77 %  O
             ______        ______ 
             100.00 %       98.85 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Co0.5Ni0.2Fe2+0.2Mg0.1Cr1.4Al0.4Fe3+0.1O4
Help on Environment: Environment: Replacing chromite in a small tabular nickel deposit in a contact between quartzite and serpentinized ultramafics.
Help on IMA Status: IMA Status: Approved IMA 1978
Help on Locality: Locality: Bon Accord deposit, Barberton, Transvaal, South Africa. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for a chromite with essential cobalt.
Help on Synonym: Synonym: ICSD 69503
  PDF 22-1084
 

Cochromite Crystallography

Help on Cell Dimensions: Cell Dimensions: a = 8.292, Z = 8; V = 570.14 Den(Calc)= 4.85
Help on Crystal System: Crystal System: Isometric - Hexoctahedral H-M Symbol (4/m 3 2/m) Space Group: F d3m
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.512(1), 1.4721(0.45), 2.947(0.35),
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Physical Properties of Cochromite

Help on Cleavage: Cleavage: {???} Indistinct
Help on Color: Color: Black.
Help on Density: Density: 5.22
Help on Diaphaneity: Diaphaneity: Opaque
Help on Fracture: Fracture: Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).
Help on Habit: Habit: Granular - Generally occurs as anhedral to subhedral crystals in matrix.
Help on Hardness: Hardness: 7 - Quartz
Help on Luster: Luster: Metallic
Help on Streak: Streak: green
 

Optical Properties of Cochromite

Help on Optical Data: Optical Data: NCalc= 2.18 - from Gladstone-Dale relationship (KC = 0.2425) where Ncalc=Dcalc*KC+1
NCalc= 2.27 - from Gladstone-Dale relationship (KC = 0.2425) where Ncalc=Dmeas*KC+1
Help on Reflectivity Reflectivity
Standardized Intensity (100%) Reflection Spectra of Cochromite in Air
λ R  ∑ R(λ) 
 480 nm   14.30   
 546 nm   13.70 
 589 nm   14.00 
 656 nm   13.90 
Calculated Relative Intensity Colors of Cochromite in Air
Relative
Intensity
   0%   70% 100% 140% 210% 280% 350% 420% 490% 560% 630%
R                      
 

Calculated Properties of Cochromite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=4.61 gm/cc
note: Specific Gravity of Cochromite =4.85 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.03
Boson Index = 0.97
Help on Photoelectric: Photoelectric: PECochromite = 17.80 barns/electron
U=PECochromite x rElectron Density= 82.11 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Cochromite is Not Radioactive
 

Cochromite Classification

Help on  Dana Class: Dana Class: 07.02.03.05 (07)Multiple Oxides
  (07.02)(A+ B++)2 X4 Spinel group
  (07.02.03)(Chromium subgroup)
 
07.02.03.01 Magnesiochromite MgCr2O4 F d3m 4/m 3 2/m
 
07.02.03.02 Manganochromite (Mn,Fe)(Cr,V)2O4 F d3m 4/m 3 2/m
 
07.02.03.03 Chromite FeCr2O4 F d3m 4/m 3 2/m
 
07.02.03.04 Nichromite (Ni,Co,Fe)(Cr,Fe,Al)2O4 F d3m 4/m 3 2/m
 
07.02.03.05 Cochromite (Co,Ni,Fe)(Cr,Al)2O4 F d3m 4/m 3 2/m
 
07.02.03.06 Zincochromite ZnCr2O4 F d3m 4/m 3 2/m
Help on  Strunz Class: Strunz Class: 04.BB.05 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.05 Cochromite (Co,Ni,Fe)(Cr,Al)2O4 F d3m 4/m 3 2/m
 
04.BB.05 Filipstadite (Mn,Mg)4SbFeO8 pseudo ISO 2/m 2/m 2/m
 
04.BB.05 Magnetite FeFe2O4 F d3m 4/m 3 2/m
 
04.BB.05 Gahnite ZnAl2O4 F d3m 4/m 3 2/m
 
04.BB.05 Chromite FeCr2O4 F d3m 4/m 3 2/m
 
04.BB.05 Galaxite (Mn,Mg)(Al,Fe)2O4 F d3m 4/m 3 2/m
 
04.BB.05 Cuprospinel (Cu,Mg)Fe2O4 F d3m 4/m 3 2/m
 
04.BB.05 Donathite? (Fe,Mg)(Cr,Fe)2O4 P 4/nnm 4/m 2/m 2/m
 
04.BB.05 Brunogeierite (Ge,Fe)Fe2O4 F d3m 4/m 3 2/m
 
04.BB.05 Coulsonite FeV2O4 F d3m 4/m 3 2/m
 
04.BB.05 Hercynite FeAl2O4 F d3m 4/m 3 2/m
 
04.BB.05 Franklinite (Zn,Mn,Fe)(Fe,Mn)2O4 F d3m 4/m 3 2/m
 
04.BB.05 Jacobsite (Mn,Fe,Mg)(Fe,Mn)2O4 F d3m 4/m 3 2/m
 
04.BB.05 Magnesiochromite MgCr2O4 F d3m 4/m 3 2/m
 
04.BB.05 Magnesioferrite MgFe2O4 F d3m 4/m 3 2/m
 
04.BB.05 Magnesiocoulsonite MgV2O4 F d3m 4/m 3 2/m
 
04.BB.05 Manganochromite (Mn,Fe)(Cr,V)2O4 F d3m 4/m 3 2/m
 
04.BB.05 Qandilite (Mg,Fe)2(Ti,Fe,Al)O4 F d3m 4/m 3 2/m
 
04.BB.05 Nichromite (Ni,Co,Fe)(Cr,Fe,Al)2O4 F d3m 4/m 3 2/m
 
04.BB.05 Spinel MgAl2O4 F d3m 4/m 3 2/m
 
04.BB.05 Ulvospinel TiFe2O4 F d3m 4/m 3 2/m
 
04.BB.05 Zincochromite ZnCr2O4 F d3m 4/m 3 2/m
 
04.BB.05 Trevorite NiFe2O4 F d3m 4/m 3 2/m
 
04.BB.05 Vuorelainenite (Mn,Fe)(V,Cr)2O4 F d3m 4/m 3 2/m
 

Other Cochromite 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 Cochromite :
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 Cochromite Specimen Label here :

Cochromite

(Co,Ni,Fe++)(Cr,Al)2O4
Dana No: 07.02.03.05 Strunz No: 04.BB.05
Locality:

 

Notes:

 

 
   
 


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