Aluminite - Occurrence, Properties, and Distribution

Aluminite is a hydrous aluminum sulfate mineral, first described in 1807 from Halle, Saxony-Anhalt, Germany. The mineral was named after the presence of aluminum in its composition.

Properties of Aluminite

The following are the key properties of Aluminite:

  • Cell Data
    • Space Group: P21/c
    • a = 7.440(1)
    • b = 15.583(2)
    • c = 11.700(2)
    • β = 110.18(2)°
    • Z = 4

  • Crystal Data
    • Monoclinic
    • Point Group: 2/m
    • As needles and fibers, to 0.1mm, commonly in reniform, nodular, or spherulitic masses, and as veinlets
    • X-ray Powder Pattern: 7.93 (100), 9.01 (90), 3.7224 (72), 4.760 (71), 3.7419 (70), 5.033 (63), 4.868 (63)

  • Chemical Composition
    Elements Content 1 Content 2
    H2O 46.76 47.11
    Al2O3 29.87 29.63
    SO3 23.37 23.26
    Total 100 100

  • Optical Properties
    • Optical Class: Biaxial (+)
    • Orientation: X = elongation
    • α = 1.459–1.460
    • β = 1.464
    • γ = 1.470
    • 2V(meas.) = ∼90°

  • Estimated Properties
    Electron density Bulk density (electron density)=1.88 g/cm3
    note: Specific gravity of Aluminite =1.80 g/cm3
    Photoelectric PEAluminite = 1.15 barns/electron
    U= PEAluminite x ρElectron density= 2.16 barns/cm3
    Fermion index Fermion index = 0.001
    Boson index = 0.998
    Radioactivity
    Aluminite is not radioactive

How to Identify Aluminite

Aluminite is a white, or grayish white, mineral, with dull luster and white streak. It is opaque and non-fluorescent. It forms botryoidal to mammillary clay-like masses. The mineral has a hardness of 1, and an average density of 1.68 g/cm3.

Global Distribution

Aluminite is distributed in the following places:

  • Morl, near Halle, Saxony-Anhalt, Germany
  • Milevsko (M¨uhlhausen), near Kralupy, Kuchelbad, Miletic, and Velvary, Czech Republic
  • G´ant, V´ertes Mountains, and at Nagyegyh´aza, Hungary
  • Mont Vernon, near Epernay, Marne, and in the Auteuil district, Paris
  • Newhaven, Sussex, England
  • Vesuvius, Campania, Italy
  • Beregovo district, near Mukachevo, Ukraine
  • Rozdol deposit; and at the Gornostayevka sulfur prospect, Kerch Peninsula
  • Vodino, near Samara, and on Mount Sokolovaya, near Saratov, Russia
  • Zaglik, Azerbaijan
  • Mbobo Mkulu Cave, near Ngodwana, Transvaal, South Africa
  • Salt Range, Punjab, India
  • Joplin, Jasper Co. Missouri, USA
  • Green River Formation, Emery Co. Utah
  • Creston, southwest of Rawlins, Carbon Co. Wyoming
  • Cottonwood Cave, Guadalupe Mountains, Eddy Co. New Mexico

Occurrence of Aluminite and Useful Mineral Association

Aluminite occurs in sulfur deposits, clays or lignites, formed by the reaction of sulfate-bearing solutions from the decomposition of marcasite, or pyrite, at moderate temperatures with aluminous silicates.

It is closely associated with goethite, dolomite, celestine, gypsum, epsomite, gibbsite, and basaluminite.

References

Tell Us What You Think

Do you have a review, update or anything you would like to add to this article?

Leave your feedback
Submit