Vauxite Mineral Data

General Vauxite Information

Chemical Formula:

Fe++Al2(PO4)2(OH)2•6(H2O)

Composition:

Molecular Weight = 441.86 gm

Aluminum 12.21 % Al 23.08 % Al₂O₃

Iron 12.64 % Fe 16.26 % FeO

Phosphorus 14.02 % P 32.12 % P₂O₅

Hydrogen 3.19 % H 28.54 % H₂O

Oxygen 57.93 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Fe²⁺Al₂(PO₄)₂(OH)₂•6(H₂O)

IMA Status:

Valid Species (Pre-IMA) 1922

Locality:

Siglo XX tin mines, Llallagua, Potosi, Bolivia. Link to MinDat.org Location Data.

Name Origin:

Named for George Vaux, Jr. (1863-1927), mineral collector, Bryn Mawr, Pennsylvania.

Name Pronunciation:

Vauxite

Synonym:

ICSD 24603

PDF 33-640

Vauxite Image

Images:

Sigloite Vauxite

Comments: Lime green, crystalline aggregate of sigloite on massive, blue vauxite.
Location: Llallagua, Potosi Department, Bolivia. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

Images:

Vauxite

Comments: Crystals of vauxite to 1.4mm.
Location: Siglo Mine, Llallagua, Bolivia. Scale: Picture size 3 cm.
© John Veevaert

Vauxite Crystallography

Axial Ratios:

a:b:c =0.7881:1:0.5309

Cell Dimensions:

a = 9.142, b = 11.599, c = 6.158, Z = 2; alpha = 98.29°, beta = 91.93°, gamma = 108.27° V = 613.24 Den(Calc)= 2.39

Crystal System:

Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1

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

By Intensity(I/I_o): 10.85(1), 5.457(0.2), 5.908(0.12),

Physical Properties of Vauxite

Cleavage:

None

Color:

Sky blue, Dark blue.

Density:

2.4

Diaphaneity:

Transparent to Translucent

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Habit:

Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)

Habit:

Tabular - Form dimensions are thin in one direction.

Hardness:

3.5 - Copper Penny

Luminescence:

Fluorescent.

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Vauxite

Gladstone-Dale:

CI meas= 0.011 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.011 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2317,KPDmeas= 0.2317,KC= 0.2342
Ncalc = 1.56

Optical Data:

Biaxial (+), a=1.551, b=1.555, g=1.562, bire=0.0110, 2V(Calc)=76, 2V(Meas)=32. Dispersion r > v strong.

Pleochroism (x):

colorless.

Pleochroism (y):

blue.

Pleochroism (z):

colorless.

Calculated Properties of Vauxite

Electron Density:

Bulk Density (Electron Density)=2.43 gm/cc
note: Specific Gravity of Vauxite =2.40 gm/cc.

Fermion Index:

Fermion Index = 0.0029623658
Boson Index = 0.9970376342

Photoelectric:

PE_Vauxite= 4.73 barns/electron
U=PE_Vauxite x rElectron Density= 11.50 barns/cc.

Radioactivity:

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

Vauxite Classification

Dana Class:

42.11.14.01 (42)Hydrated Phosphates, etc., Containing Hydroxyl or Halogen

(42.11)where (AB)4 (XO4)3 Zq ï¿½ x(H2O)

(42.11.14)Vauxite Group

42.11.14.01 Vauxite FeAl2(PO4)2(OH)2•6(H2O) P1 1

42.11.14.02 Paravauxite FeAl2(PO4)2(OH)2•8(H2O) P1 1

42.11.14.03 Sigloite FeAl2(PO4)2(OH)3•5(H2O) P1 1

42.11.14.04 Gordonite MgAl2(PO4)2(OH)2•8(H2O) P1 1

42.11.14.05 Mangangordonite (Mn,Fe,Mg)Al2(PO4)2(OH)2•8(H2O) P1 1

42.11.14.06 Kastningite! (Mn,Fe,Mg)Al2(PO4)2(OH)2•8(H2O) P1 1

42.11.14.07 Maghrebite! MgAl2(AsO4)2(OH)2•8H2O P1 1

Strunz Class:

08.DC.35 08 - PHOSPHATES, ARSENATES, VANADATES

08.D - Phosphates, etc

08.DC -With only medium-sized cations, (OH, etc.):RO4 = 1:1 and < 2:1

08.DC.35 Vauxite FeAl2(PO4)2(OH)2•6(H2O) P1 1

Other Vauxite Information

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8)

See Also:

Links to other databases for Vauxite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (MinSocAm)
10 - Handbook of Mineralogy (UofA)
11 - MinDAT
12 - Mineralienatlas (Deutsch)
13 - Online Mineral Museum
14 - QUT Mineral Atlas
15 - Ruff.Info
16 - WWW-MINCRYST

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

Vauxite

Fe++Al2(PO4)2(OH)2•6(H2O)
Dana No: 42.11.14.01 Strunz No: 08.DC.35
Locality:

Notes:

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