Halotrichite Mineral Data

General Halotrichite Information

Chemical Formula:

Fe++Al2(SO4)4•22(H2O)

Composition:

Molecular Weight = 890.40 gm

Aluminum 6.06 % Al 11.45 % Al₂O₃

Iron 6.27 % Fe 8.07 % FeO

Hydrogen 4.98 % H 44.51 % H₂O

Sulfur 14.41 % S 35.97 % SO₃

Oxygen 68.28 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Fe²⁺Al₂(SO₄)₄•22(H₂O)

IMA Status:

Valid Species (Pre-IMA) 1839

Locality:

Link to MinDat.org Location Data.

Name Origin:

From the Latin, halotrichum ="hairy salt."

Name Pronunciation:

Halotrichite + Pronunciation

Synonym:

Feather Alum

Haarsalz

Iron Alum

Halotrichite Image

Images:

Halotrichite

Comments: White, fibrous halotrichite on rock.
Location: Willi Agatz Mine, Dresden, Saxony, Germany. Scale: Picture size 4.5 cm.
© Thomas Witzke / Abraxas-Verlag

Images:

Boothite Halotrichite

Comments: Pale blue earthy boothite with white halotrichite.
Location: Copiapo, Atacama, Chile. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Images:

Szomolnokite Halotrichite

Comments: Tan powdery szomolnokite crust on silky fibrous halotrichite with yellow metavoltine.
Location: Markey Mine, Red Canyon, San Juan County, Utah, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Halotrichite Crystallography

Axial Ratios:

a:b:c =0.8445:1:0.2543

Cell Dimensions:

a = 20.519, b = 24.297, c = 6.181, Z = 4; beta = 100.9° V = 3,025.94 Den(Calc)= 1.95

Crystal System:

Monoclinic - Sphenoidal H-M Symbol (2) Space Group: P 2

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

By Intensity(I/I_o): 3.5(1), 4.3(1), 4.81(1),

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Forms: ( 1 3 1) ( 1 1 0) ( 1 1 1)

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Physical Properties of Halotrichite

Cleavage:

{010} Indistinct

Color:

Colorless, Green, Gray white, Yellow, White.

Density:

1.78 - 1.9, Average = 1.84

Diaphaneity:

Transparent to translucent

Fracture:

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

Habit:

Encrustations - Forms crust-like aggregates on matrix.

Habit:

Fibrous - Crystals made up of fibers.

Hardness:

1.5-2 - Talc-Gypsum

Luminescence:

Non-fluorescent.

Luster:

Silky

Streak:

white

Optical Properties of Halotrichite

Gladstone-Dale:

CI meas= -0.039 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.02 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2489,KPDmeas= 0.2638,KC= 0.2539
Ncalc = 1.45 - 1.5

Optical Data:

Biaxial (-), a=1.48, b=1.486, g=1.49, bire=0.0100, 2V(Calc)=78, 2V(Meas)=35. Dispersion none.

Pleochroism (x):

none.

Pleochroism (y):

none.

Pleochroism (z):

none.

Calculated Properties of Halotrichite

Electron Density:

Bulk Density (Electron Density)=2.03 gm/cc
note: Specific Gravity of Halotrichite =1.95 gm/cc.

Fermion Index:

Fermion Index = 0.0027453011
Boson Index = 0.9972546989

Photoelectric:

PE_Halotrichite= 2.92 barns/electron
U=PE_Halotrichite x rElectron Density= 5.93 barns/cc.

Radioactivity:

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

Halotrichite Classification

Dana Class:

29.07.03.02 (29)Hydrated Acid and Sulfates

(29.07)where A (B)2 (XO4)4 � x(H2O)

(29.07.03)Halotrichite Group (Monoclinic with 22 H2O)

29.07.03.01 Pickeringite MgAl2(SO4)4•22(H2O) P 2 2

29.07.03.02 Halotrichite FeAl2(SO4)4•22(H2O) P 2 2

29.07.03.03 Apjohnite MnAl2(SO4)4•22(H2O) P 2₁/c 2/m

29.07.03.04 Dietrichite (Zn,Fe,Mn)Al2(SO4)4•22(H2O) P 2₁/c 2/m

29.07.03.05 Bilinite FeFe2(SO4)4•22(H2O) P 2₁/c 2/m

29.07.03.06 Redingtonite (Fe,Mg,Ni)(Cr,Al)2(SO4)4•22(H2O) Mono

29.07.03.07 Wupatkiite (Co,Mg,Ni)Al2(SO4)4•22(H2O) P 2₁/c 2/m

Strunz Class:

07.CB.85 07 - SULFATES (SELENATES, TELLURATES)

07.C - Sulfates (selenates, etc.) without Additional Anions, with H2O

07.CB -With only medium-sized cations

07.CB.85 Bilinite FeFe2(SO4)4•22(H2O) P 2₁/c 2/m

07.CB.85 Apjohnite MnAl2(SO4)4•22(H2O) P 2₁/c 2/m

07.CB.85 Dietrichite (Zn,Fe,Mn)Al2(SO4)4•22(H2O) P 2₁/c 2/m

07.CB.85 Halotrichite FeAl2(SO4)4•22(H2O) P 2 2

07.CB.85 Pickeringite MgAl2(SO4)4•22(H2O) P 2 2

07.CB.85 Redingtonite (Fe,Mg,Ni)(Cr,Al)2(SO4)4•22(H2O) Mono

07.CB.85 Wupatkiite (Co,Mg,Ni)Al2(SO4)4•22(H2O) P 2₁/c 2/m

Other Halotrichite Information

See Also:

Links to other databases for Halotrichite :
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 - Handbook of Mineralogy (UofA)
13 - MinDAT
14 - Mineralienatlas (Deutsch)
15 - Online Mineral Museum
16 - QUT Mineral Atlas
17 - Ruff.Info

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

Halotrichite

Fe++Al2(SO4)4•22(H2O)
Dana No: 29.07.03.02 Strunz No: 07.CB.85
Locality:

Notes:

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