May 12 2014
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