Wilcoxite Mineral Data

General Wilcoxite Information

Chemical Formula:

MgAl(SO4)2F•18(H2O)

Composition:

Molecular Weight = 586.69 gm

Magnesium 4.14 % Mg 6.87 % MgO

Aluminum 4.60 % Al 8.69 % Al₂O₃

Hydrogen 6.18 % H 55.27 % H₂O

Sulfur 10.93 % S 27.29 % SO₃

Oxygen 70.90 % O

Fluorine 3.24 % F 3.24 % F

- % F -1.36 % -O=F₂

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

MgAl(SO₄)₂F•18(H₂O)

Environment:

Post mining product in oxidizable sulfide deposits containing fluorine bearing minerals.

IMA Status:

Approved IMA 1983

Locality:

Lone Pine mine, Catron County, New Mexico. Link to MinDat.org Location Data.

Name Origin:

Named after William Wilcox, who discovered this mining district in 1879. He was killed by Apache Indians in 1880.

Name Pronunciation:

Wilcoxite + Pronunciation

Wilcoxite Image

Images:

Wilcoxite

Comments: Small, transparent crystals of wilcoxite.
Location: Lichtenberg Mine, Ronneburg U Deposit, Gera district, Thuringia, Germany. Scale: Picture size 0.8 mm.
© Thomas Witzke / Abraxas-Verlag

Wilcoxite Crystallography

Axial Ratios:

a:b:c =2.2406:1:1.018

Cell Dimensions:

a = 14.9, b = 6.65, c = 6.77, Z = 1; alpha = 117.433°, beta = 100.583°, gamma = 89.167° V = 585.18 Den(Calc)= 1.66

Crystal System:

Triclinic Space Group: P 1,P1

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

By Intensity(I/I_o): 4.908(1), 5.654(0.9), 4.371(0.6),

Physical Properties of Wilcoxite

Color:

Colorless, White.

Density:

1.58

Diaphaneity:

Transparent to Translucent

Habit:

Efflorescences - Crystals covering matrix, generally produced from transpiro-evaporation.

Habit:

Encrustations - Forms crust-like aggregates on matrix.

Habit:

Water Soluble - Water soluble mineral.

Hardness:

2 - Gypsum

Streak:

white

Optical Properties of Wilcoxite

Gladstone-Dale:

CI meas= -0.016 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.039 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2591,KPDmeas= 0.2738,KC= 0.2695
Ncalc = 1.43 - 1.45

Optical Data:

Biaxial (-), a=1.424, b=1.436, g=1.438, bire=0.0140, 2V(Calc)=44, 2V(Meas)=48. Dispersion not discernible.

Calculated Properties of Wilcoxite

Electron Density:

Bulk Density (Electron Density)=1.67 gm/cc
note: Specific Gravity of Wilcoxite =1.58 gm/cc.

Fermion Index:

Fermion Index = 0.0053122098
Boson Index = 0.9946877902

Photoelectric:

PE_Wilcoxite= 1.06 barns/electron
U=PE_Wilcoxite x rElectron Density= 1.77 barns/cc.

Radioactivity:

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

Wilcoxite Classification

Dana Class:

31.09.09.01 (31)Hydrated Sulfates Containing Hydroxyl or Halogen

(31.09)where (A+ B++) (XO4) Zqï¿½x(H2O)

(31.09.09)Dana Group

31.09.09.01 Wilcoxite MgAl(SO4)2F•18(H2O) P 1,P1 Tri

Strunz Class:

07.DE.45 07 - SULFATES (SELENATES, TELLURATES)

07.D - Sulfates (selenates, etc.) with additional anions, with H2O

07.DE -With only medium-sized cations; unclassified

07.DE.45 Wilcoxite MgAl(SO4)2F•18(H2O) P 1,P1 Tri

Other Wilcoxite Information

References:

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

See Also:

Links to other databases for Wilcoxite :
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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Print or Cut-and-Paste your Wilcoxite Specimen Label here :

Wilcoxite

MgAl(SO4)2F•18(H2O)
Dana No: 31.09.09.01 Strunz No: 07.DE.45
Locality:

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