Aluminite Mineral Data

General Aluminite Information

Chemical Formula:

Al2(SO4)(OH)4•7(H2O)

Composition:

Molecular Weight = 344.16 gm

Aluminum 15.68 % Al 29.63 % Al₂O₃

Hydrogen 5.27 % H 47.11 % H₂O

Sulfur 9.32 % S 23.26 % SO₃

Oxygen 69.73 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Al₂(SO₄)(OH)₄•7(H₂O)

Environment:

Formed in recent or Tertiary clays, marls, and lignites by the action of sulfate solutions derived from the alteration of pyrite or marcasite on aluminous silicates.

IMA Status:

Valid Species (Pre-IMA) 1807

Locality:

Halle, Saxony, Germany. Link to MinDat.org Location Data.

Name Origin:

Named after its chemical composition.

Name Pronunciation:

Aluminite + Pronunciation

Synonym:

ICSD 2234

PDF 43-669

Websterite

Aluminite Image

Images:

Aluminite

Comments: Snow-white, very pure nodules of aluminite.
Location: Newhaven, Sussex, Great Britain. Scale: 5.5 x 3 cm.
© John Veevaert

Aluminite Crystallography

Axial Ratios:

a:b:c =0.4774:1:0.7508

Cell Dimensions:

a = 7.44, b = 15.583, c = 11.7, Z = 4; beta = 110.18° V = 1,273.20 Den(Calc)= 1.80

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2₁/c

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

By Intensity(I/I_o): 8.977(1), 7.791(0.87), 4.696(0.48),

Physical Properties of Aluminite

Cleavage:

None

Color:

White, Grayish white.

Density:

1.66 - 1.7, Average = 1.68

Diaphaneity:

Opaque

Fracture:

Earthy - Dull, clay-like fractures with no visible crystalline affinities, (e.g. howlite).

Habit:

Botryoidal - "Grape-like" rounded forms (e.g.. malachite).

Habit:

Earthy - Dull, clay-like texture with no visible crystalline affinities, (e.g. howlite).

Habit:

Mammillary - Larger "breast-like" rounded forms resembling botryoidal (e.g. malachite).

Hardness:

1 - Talc

Luminescence:

Non-fluorescent.

Luster:

Earthy (Dull)

Streak:

white

Optical Properties of Aluminite

Gladstone-Dale:

CI meas= -0.052 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.018 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.258,KPDmeas= 0.2764,KC= 0.2627
Ncalc = 1.44 - 1.47

Optical Data:

Biaxial (+), a=1.459, b=1.464, g=1.47, bire=0.0110, 2V(Calc)=86, 2V(Meas)=90. Dispersion none.

Pleochroism (x):

colorless.

Calculated Properties of Aluminite

Electron Density:

Bulk Density (Electron Density)=1.88 gm/cc
note: Specific Gravity of Aluminite =1.80 gm/cc.

Fermion Index:

Fermion Index = 0.0010414022
Boson Index = 0.9989585978

Photoelectric:

PE_Aluminite= 1.15 barns/electron
U=PE_Aluminite x rElectron Density= 2.16 barns/cc.

Radioactivity:

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

Aluminite Classification

Dana Class:

31.07.04.01 (31)Hydrated Sulfates Containing Hydroxyl or Halogen

(31.07)where (A+ B++)2 (XO4) Zqï¿½x(H2O)

(31.07.04)Dana Group

31.07.04.01 Aluminite Al2(SO4)(OH)4•7(H2O) P 2₁/c 2/m

31.07.04.02 Mangazeite! Al2(SO4)(OH)4•3H2O P1 or P1 Tri

Strunz Class:

07.DC.05 07 - SULFATES (SELENATES, TELLURATES)

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

07.DC -With only medium-sized cations; chains of corner-sharing octahedra

07.DC.05 Aluminite Al2(SO4)(OH)4•7(H2O) P 2₁/c 2/m

07.DC.05 Meta-aluminite Al2(SO4)(OH)4•5(H2O) P 2₁/c ? 2/m

Other Aluminite Information

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Ford32)

See Also:

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

Aluminite

Al2(SO4)(OH)4•7(H2O)
Dana No: 31.07.04.01 Strunz No: 07.DC.05
Locality:

Notes:

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