Bernalite Mineral Data

General Bernalite Information

Chemical Formula:

Fe(OH)3

Composition:

Molecular Weight = 108.14 gm

Zinc 1.21 % Zn 1.51 % ZnO

Iron 45.96 % Fe 65.71 % Fe₂O₃

Silicon 1.82 % Si 3.89 % SiO₂

Hydrogen 2.80 % H 24.99 % H₂O

Lead 3.83 % Pb 4.13 % PbO

Oxygen 44.38 % O

______ ______

100.00 % 100.22 % = TOTAL OXIDE

Empirical Formula:

Fe³⁺_0.89Si_0.07Pb_0.02Zn_0.02(OH)₃

Environment:

On a museum specimen from a metamorphosed Pb-Zn deposit, probably from the surface oxidation zone.

IMA Status:

Approved IMA 1993

Locality:

From the Proprietary mine, Broken Hill, New South Wales, Australia. Link to MinDat.org Location Data.

Name Origin:

To honor John Desmond Bernal (1901-1971), eminent British crystallographer and historian of science.

Name Pronunciation:

Bernalite + Pronunciation

Synonym:

ICSD 73441

PDF 46-1436

Bernalite Image

Images:

Bernalite

Comments: B&W image of pseudo-octahedral crystals of bernalite on goethite. (AmMin, v78:827).
Location: Proprietary mine, Broken Hill, New South Wales, Australia. Scale: Scale Bar 3 mm.
© American Mineralogist

Bernalite Crystallography

Axial Ratios:

a:b:c =1:1:0.9913

Cell Dimensions:

a = 7.6191, b = 7.6191, c = 7.5534, Z = 8; V = 438.48 Den(Calc)= 3.28

Crystal System:

Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pmmn

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 3.784(1), 1.692(0.17), 2.393(0.16),

Physical Properties of Bernalite

Cleavage:

None

Color:

Yellow green, Dark bottle green.

Density:

3.32

Diaphaneity:

Transparent to Translucent

Hardness:

4 - Fluorite

Luster:

Vitreous - Resinous

Streak:

apple green

Optical Properties of Bernalite

Gladstone-Dale:

CI meas= 0.09 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.079 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2835,KPDmeas= 0.2801,KC= 0.3079
Ncalc = 2.01 - 2.02

Optical Data:

Biaxial (?), b=1.92-1.94

Calculated Properties of Bernalite

Electron Density:

Bulk Density (Electron Density)=3.24 gm/cc
note: Specific Gravity of Bernalite =3.28 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Bernalite= 73.91 barns/electron
U=PE_Bernalite x rElectron Density= 239.24 barns/cc.

Radioactivity:

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

Bernalite Classification

Dana Class:

06.03.05.03 (06)Hydroxides and Oxides Containing Hydroxyl

(06.03)with (OH)3 or (OH)6 groups

(06.03.05)Dzhalindite Group

06.03.05.01 Dzhalindite In(OH)3 I m3 2/m 3

06.03.05.02 Sohngeite Ga(OH)3 I m3 2/m 3

06.03.05.03 Bernalite Fe(OH)3 Pmmn 2/m 2/m 2/m

Strunz Class:

04.FC.05 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.F - Hydroxides (without V or U)

04.FC -Hydroxides with OH, without H2O; corner-sharing octahedra

04.FC.05 Bernalite Fe(OH)3 Pmmn 2/m 2/m 2/m

04.FC.05 Dzhalindite In(OH)3 I m3 2/m 3

04.FC.05 Sohngeite Ga(OH)3 I m3 2/m 3

Other Bernalite Information

References:

NAME( AntBidBlaNic3) PHYS. PROP.(Am.Min.,v78,p827, v91,p220) OPTIC PROP.(Am.Min.,Vol.78,p827-834,1993)

See Also:

Links to other databases for Bernalite :
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 Bernalite Specimen Label here :

Bernalite

Fe(OH)3
Dana No: 06.03.05.03 Strunz No: 04.FC.05
Locality:

Notes:

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