Manganochromite Mineral Data

General Manganochromite Information

Chemical Formula:

(Mn,Fe++)(Cr,V)2O4

Composition:

Molecular Weight = 225.53 gm

Manganese 19.49 % Mn 25.16 % MnO

Vanadium 0.90 % V 1.33 % V₂O₃

Chromium 43.80 % Cr 64.02 % Cr₂O₃

Iron 7.43 % Fe 9.56 % FeO

Oxygen 28.38 % O

______ ______

100.00 % 100.07 % = TOTAL OXIDE

Empirical Formula:

Mn²⁺_0.8Fe²⁺_0.3Cr_1.9V³⁺_0.04O₄

Environment:

Extensional gash vein in a metamorphosed hydrothermal pyrite deposit.

IMA Status:

Approved IMA 1978

Locality:

Nairne deposit, near Brukunga, 47 km east of Adelaide, South Australia. Link to MinDat.org Location Data.

Name Origin:

Named for its MANGANese in the composition and relationship to magnesiochromite.

Name Pronunciation:

Manganochromite

Manganochromite Image

Images:

Manganochromite

Comments: B&W polished section image showing a somewhat irregular manganochromite grain (pale grey) lying between hexagonal pyrrhotite (white) and a large diopside crystal (grey).
Location: Nairne pyrite formation, (Shepard's Hill Quarry), Brukunga, 47km east of Adelaide, South Australia. (AmMin, v63:1166). Scale: FOV 450 µm.
© American Mineralogist

Manganochromite Crystallography

Cell Dimensions:

a = 8.47, Z = 8; V = 607.65 Den(Calc)= 4.93

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): 2.55(1), 1.63(0.7), 1.5(0.6),

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Physical Properties of Manganochromite

Color:

Grayish black.

Density:

4.86

Diaphaneity:

Opaque

Habit:

Microscopic Crystals - Crystals visible only with microscopes.

Hardness:

5.5 - Knife Blade

Luster:

Metallic

Optical Properties of Manganochromite

Optical Data:

Isotropic.

NCalc= 2.27 - from Gladstone-Dale relationship (KC = 0.2569) where Ncalc=Dcalc*KC+1
NCalc= 2.25 - from Gladstone-Dale relationship (KC = 0.2569) where Ncalc=Dmeas*KC+1

RL Color:

Gbrownish gray.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Manganochromite in Air**
λ	R	∑ R(λ)
470 nm	16.80
546 nm	16.50
589 nm	16.50
650 nm	16.30

**Calculated Relative Intensity Colors of Manganochromite in Air**
Relative Intensity	0%	60%	100%	120%	180%	240%	300%	360%	420%	480%	540%
R

Calculated Properties of Manganochromite

Electron Density:

Bulk Density (Electron Density)=4.65 gm/cc
note: Specific Gravity of Manganochromite =4.93 gm/cc.

Fermion Index:

Fermion Index = 0.04
Boson Index = 0.96

Photoelectric:

PE_{Manganochromite}= 17.63 barns/electron
U=PE_{Manganochromite} x rElectron Density= 81.95 barns/cc.

Radioactivity:

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

Manganochromite Classification

Dana Class:

07.02.03.02 (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 Manganochromite Information

References:

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

See Also:

Links to other databases for Manganochromite :
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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Manganochromite

(Mn,Fe++)(Cr,V)2O4
Dana No: 07.02.03.02 Strunz No: 04.BB.05
Locality:

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