Hercynite Mineral Data

General Hercynite Information

Chemical Formula:

Fe++Al2O4

Composition:

Molecular Weight = 173.81 gm

Aluminum 31.05 % Al 58.66 % Al₂O₃

Iron 32.13 % Fe 41.34 % FeO

Oxygen 36.82 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Fe²⁺Al₂O₄

Environment:

Magmatic.

IMA Status:

Valid Species (Pre-IMA) 1847

Locality:

Pobezovice, Czechoslovakia. Link to MinDat.org Location Data.

Name Origin:

From the old Latin, Hercynia Silva, "Forested Mountains."

Name Pronunciation:

Hercynite + Pronunciation

Synonym:

ICSD 74611

Iron Spinel

PDF 34-192

Hercynite Image

Images:

Hercynite

Comments: Brownish black granular hercynite.
Location: Nacetin, Severocesky, Czech Republic. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Hercynite Crystallography

Cell Dimensions:

a = 8.136, Z = 8; V = 538.56 Den(Calc)= 4.29

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): 2.4597(1), 1.4414(0.42), 1.5691(0.36),

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Physical Properties of Hercynite

Cleavage:

{111} Indistinct, {111} Indistinct, {111} Indistinct

Color:

Black.

Density:

3.95

Diaphaneity:

Opaque

Fracture:

Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.

Habit:

Euhedral Crystals - Occurs as well-formed crystals showing good external form.

Habit:

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

Habit:

Massive - Granular - Common texture observed in granite and other igneous rock.

Hardness:

7.5 - Garnet

Luminescence:

Non-fluorescent.

Luster:

Vitreous (Glassy)

Streak:

dark green

Optical Properties of Hercynite

Gladstone-Dale:

CI meas= -0.017 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.064 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1865,KPDmeas= 0.2025,KC= 0.1991
Ncalc = 1.79 - 1.85

Optical Data:

Isotropic, n=1.8.

Calculated Properties of Hercynite

Electron Density:

Bulk Density (Electron Density)=3.82 gm/cc
note: Specific Gravity of Hercynite =3.95 gm/cc.

Fermion Index:

Fermion Index = 0.0069886167
Boson Index = 0.9930113833

Photoelectric:

PE_Hercynite= 10.57 barns/electron
U=PE_Hercynite x rElectron Density= 40.35 barns/cc.

Radioactivity:

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

Hercynite Classification

Dana Class:

07.02.01.03 (07)Multiple Oxides

(07.02)(A+ B++)2 X4 Spinel group

(07.02.01)(Aluminum subgroup)

07.02.01.01 Spinel MgAl2O4 F d3m 4/m 3 2/m

07.02.01.02 Galaxite (Mn,Mg)(Al,Fe)2O4 F d3m 4/m 3 2/m

07.02.01.03 Hercynite FeAl2O4 F d3m 4/m 3 2/m

07.02.01.04 Gahnite ZnAl2O4 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 Hercynite Information

References:

NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Ford32)

See Also:

Links to other databases for Hercynite :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Athena
5 - EUROmin Project
6 - Ecole des Mines de Paris
7 - Franklin Minerals(Dunn)
8 - GeoScienceWorld
9 - Google Images
10 - Google Scholar
11 - Handbook of Mineralogy (MinSocAm)
12 - MinDAT
13 - Mineralienatlas (Deutsch)
14 - Online Mineral Museum
15 - QUT Mineral Atlas
16 - Ruff.Info
17 - University of Colorado - Mineral Structure Data
18 - WWW-MINCRYST

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

Hercynite

Fe++Al2O4
Dana No: 07.02.01.03 Strunz No: 04.BB.05
Locality:

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