Mineralogy Database

Maghemite Mineral Data

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General Maghemite Information

Help on Chemical  Formula: Chemical Formula: gamma-Fe+++2O3
Help on Composition: Composition: Molecular Weight = 159.69 gm
   Iron    69.94 %  Fe  100.00 % Fe2O3
   Oxygen  30.06 %  O
          ______        ______ 
          100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Fe3+2O3
Help on Environment: Environment: Formed by weathering or low-temperature oxidation of spinels containing ferrous iron, commonly magnetite or titanian magnetite. Widespread yellow pigment in sediments.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1927
Help on Locality: Locality: Iron mountain mine, 9.5 miles NW of Redding, Shasta Co., California. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: From MAGnetite and HEMatite, in allusion to the mineral's magnetism and composition.
Help on Name Pronunciation: Name Pronunciation: Maghemite + Pronunciation Say MAGHEMITE

Maghemite Image

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Comments: Fine-grained massive maghemite intermixed with hematite.
Location: Gara Djebilet, Algeria. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Maghemite Crystallography

Help on Cell Dimensions: Cell Dimensions: a = 8.339, Z = 12; V = 579.89 Den(Calc)= 5.49
Help on Crystal System: Crystal System: Isometric - Tetartoidal H-M Symbol (2 3) Space Group: P 213
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 1.61(1), 2.52(1), 2.95(1),

Physical Properties of Maghemite

Help on Cleavage: Cleavage: None
Help on Color: Color: Dark brown.
Help on Density: Density: 4.9
Help on Diaphaneity: Diaphaneity: Opaque
Help on Fracture: Fracture: Sub Conchoidal - Fractures developed in brittle materials characterized by semi-curving surfaces.
Help on Habit: Habit: Massive - Granular - Common texture observed in granite and other igneous rock.
Help on Habit: Habit: Massive - Uniformly indistinguishable crystals forming large masses.
Help on Hardness: Hardness: 6 - Orthoclase
Help on Luster: Luster: Metallic
Help on Magnetism: Magnetism: Strongly magnetic
Help on Streak: Streak: brown

Optical Properties of Maghemite

Help on Optical Data: Optical Data: Isotropic.
  NCalc= 2.73 - from Gladstone-Dale relationship (KC = 0.315) where Ncalc=Dcalc*KC+1
NCalc= 2.54 - from Gladstone-Dale relationship (KC = 0.315) where Ncalc=Dmeas*KC+1
Help on RL Color: RL Color: White to bluish gray.
Help on Reflectivity Reflectivity
Standardized Intensity (100%) Reflection Spectra of Maghemite in Air
λ R  ∑ R(λ) 
 400 nm   31.50   
 420 nm   30.20 
 440 nm   28.50 
 460 nm   27.60 
 480 nm   26.60 
 500 nm   26.00 
 520 nm   25.50 
 540 nm   24.80 
 560 nm   24.00 
 580 nm   23.20 
 600 nm   22.40 
 620 nm   22.00 
 640 nm   21.60 
 660 nm   21.20 
 680 nm   20.80 
 700 nm   20.40 
Calculated Relative Intensity Colors of Maghemite in Air
   0%   40%   80% 100% 120% 160% 200% 240% 280% 320% 360% 390%

Calculated Properties of Maghemite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=5.23 gm/cc
note: Specific Gravity of Maghemite =5.49 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PEMaghemite = 21.37 barns/electron
U=PEMaghemite x rElectron Density= 111.70 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Maghemite is Not Radioactive

Maghemite Classification

Help on  Dana Class: Dana Class: (04)Simple Oxides
  (04.03)with a cation charge of 3+ (A+++2 O3)
  (04.03.07)Dana Group Maghemite gamma-Fe2O3 P 213 2 3 Bixbyite (Mn,Fe)2O3 I a3 2/m 3
Help on  Strunz Class: Strunz Class: 04.BB.15 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.15 Maghemite gamma-Fe2O3 P 213 2 3

Other Maghemite Information

Help on References: References: NAME( MinRec) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic3)
Help on See Also: See Also: Links to other databases for Maghemite :
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

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Dana No: Strunz No: 04.BB.15





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