Nichromite Mineral Data

General Nichromite Information

Chemical Formula:

(Ni,Co,Fe++)(Cr,Fe+++,Al)2O4

Composition:

Molecular Weight = 220.53 gm

Aluminum 3.67 % Al 6.94 % Al₂O₃

Chromium 30.65 % Cr 44.80 % Cr₂O₃

Iron 12.66 % Fe 6.52 % FeO / 10.86 % Fe₂O₃

Cobalt 10.69 % Co 13.59 % CoO

Nickel 13.31 % Ni 16.93 % NiO

Oxygen 29.02 % O

______ ______

100.00 % 99.64 % = TOTAL OXIDE

Empirical Formula:

Ni_0.5Co_0.4Fe²⁺_0.2Cr_1.3Fe³⁺_0.3Al_0.3O₄

Environment:

Replacing chromite in a small tabular nickel deposit at the contact between quartzite and serpentinized ultramafics.

IMA Status:

Approved IMA 1978

Locality:

Bon Accord deposit, Barberton, Transvaal, South Africa. Link to MinDat.org Location Data.

Name Origin:

Named for chromite with dominant nickel, Ni.

Name Pronunciation:

Nichromite + Pronunciation

Nichromite Crystallography

Cell Dimensions:

a = 8.316, Z = 8; V = 575.10 Den(Calc)= 5.09

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/I_o): 2.51(1), 2.95(0.55), 1.472(0.5),

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Physical Properties of Nichromite

Cleavage:

{???} Indistinct

Color:

Black.

Density:

5.24

Diaphaneity:

Opaque

Fracture:

Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).

Habit:

Granular - Generally occurs as anhedral to subhedral crystals in matrix.

Hardness:

6-6.5 - Orthoclase-Pyrite

Luster:

Metallic

Streak:

greenish gray

Optical Properties of Nichromite

Optical Data:

NCalc= 2.25 - from Gladstone-Dale relationship (KC = 0.2449) where Ncalc=Dcalc*KC+1
NCalc= 2.28 - from Gladstone-Dale relationship (KC = 0.2449) where Ncalc=Dmeas*KC+1

Calculated Properties of Nichromite

Electron Density:

Bulk Density (Electron Density)=4.84 gm/cc
note: Specific Gravity of Nichromite =5.09 gm/cc.

Fermion Index:

Fermion Index = 0.03
Boson Index = 0.97

Photoelectric:

PE_Nichromite= 20.07 barns/electron
U=PE_Nichromite x rElectron Density= 97.16 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Nichromite is Not Radioactive

Nichromite Classification

Dana Class:

07.02.03.04 (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

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 Nichromite Information

References:

NAME( AntBidBlaNic3) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Nichromite :
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 - MinDAT
9 - Mineralienatlas (Deutsch)
10 - Online Mineral Museum
11 - QUT Mineral Atlas
12 - Ruff.Info
13 - WWW-MINCRYST

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Print or Cut-and-Paste your Nichromite Specimen Label here :

Nichromite

(Ni,Co,Fe++)(Cr,Fe+++,Al)2O4
Dana No: 07.02.03.04 Strunz No: 04.BB.05
Locality:

Notes:

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