Jun 3 2014
The following are the key properties of Armangite:
- Cell Data
- Space Group: P3
- a = 13.491(2)
- c = 8.855(1)
- Z = 1
- Crystal Data
- Hexagonal
- Point Group: 3
- As tiny short hexagonal prisms, terminated by a trigonal pyramid
- Twinning: On {1120}
- X-ray Powder Pattern: 2.762 (100), 2.94 (70), 2.428 (70), 1.759 (60), 3.92 (50), 1.676 (50), 1.459 (50)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
Content 3 |
| As2O3 |
42.92 |
48.82 |
48.06 |
| MnO |
45.06 |
47.06 |
49.78 |
| CO2 |
5.08 |
- |
1.19 |
| CaO |
2.83 |
- |
- |
| FeO |
2.19 |
2.49 |
- |
| H2O |
0.71 |
0.81 |
0.97 |
| MgO |
0.49 |
- |
- |
| Sb2O3 |
0.40 |
0.46 |
- |
| PbO |
0.32 |
0.36 |
- |
| insol. |
0.20 |
- |
- |
| Total |
100.20 |
[100.00] |
100.00 |
- Optical Properties
- Optical Class: Uniaxial (–)
- ω = 2.01
- ε = 1.99
- Estimated Properties
| Electron density |
Bulk Density (Electron Density) = 4.09 g/cm3
note: Specific Gravity of Armangite = 4.43 g/cm3 |
| Photoelectric |
PEArmangite = 35.79 barns/electron
U = PEArmangite x ρElectron Density = 146.37 barns/cm3 |
| Fermion index |
Fermion Index = 0.0001539734
Boson Index = 0.9998460266 |
Radioactivity
|
Armangite is not radioactive
|
How to Identify Armangite
Aramangite is black in color, with a brown streak and cleavages. It has a relative hardness of 4 and its density is 4.43 g/cm3.
Global Distribution
Armangite is largely distributed in Langban, Varmland, Sweden.
Occurrence of Armangite and Useful Mineral Association
Armangite occurs as a museum specimen obtained from a metamorphosed Fe-Mn deposit. It is closely associated with hausmannite, manganarsite, fluorite, hematite, barite, dolomite, and calcite.
References