May 9 2013
Schallerite was discovered in 1924, in the Franklin Mining District of the USA. This mineral is named after Wakdemar Theodore Shaller, a mineralogist.
Properties of Schallerite
The key physical properties of Schallerite are as below:
- Cell Data
- Space group: P3m1
- a = 13.43
- c=14.31
- Z = 2.
- Crystal Data
- Hexagonal
- Point group: n.d
- Crystals – structure of Schallerite crystals is hemimorphic, with steep pyramids that are terminated by dull f0001g and f0001g pedions. As slightly rectangular aggregates that resemble augen; also granular to massive.
- X-ray powder pattern: 1.688 (100), 2.673 (60), 1.511 (60), 2.466 (50), 2.022 (50), 3.55 (40), 1.975 (40).
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
Content 3 |
| SiO2 |
32.0 |
31.51 |
31.27 |
| TiO2 |
- |
0.03 |
- |
| Al2O3 |
- |
0.01 |
- |
| Fe2O3 |
2.6 |
- |
- |
| As2O3 |
12.81 |
11.41 |
12.87 |
| FeO |
- |
0.14 |
- |
| MnO |
42.5 |
48.90 |
49.22 |
| ZnO |
1.6 |
- |
- |
| MgO |
2.3 |
0.06 |
- |
| CaO |
- |
0.02 |
- |
| Cl |
0.0 |
0.11 |
- |
| H2O |
6.82 |
[6.73] |
6.64 |
- Optical Properties
- Optical class: Uniaxial
- ω = 1.681–1.704
- ε = 1.643–1.679.
- Estimated Properties
| Electron density |
Bulk density (electron density) = 3.24 g/cm3
note: Specific gravity of Schallerite = 3.37 g/cm3 |
| Photoelectric |
PESchallerite = 16.95 barns/electron
U = PESchallerite x ρelectron density = 54.89 barns/cm3 |
| Fermion index |
Fermion index = 0.007
Boson index = 0.992 |
Radioactivity
|
GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Schallerite is not radioactive. |
How to Identify Schallerite
Schallerite appears in the form of light-to-reddish brown mineral on the fields. It is in the form of translucent, uniformly undistinguishable crystals that form large masses. This mineral has a vitreous, waxy luster with a light brown streak. The density of these crystals is 3.37 g/cm3, hardness ranges from 4.5-5 (close to Apatite). Schallerite is non-magnetic and non-flouorescent.
Global Distribution
Schallerite is widely distributed in the following locations:
- USA- from Betts Manganese Mines, Hampshire, Massachusetts and Franklin Mining District, New Jersey
- Sweden –from Persberg District, Varmland
- Romania – from Suceava District
- Austria – from Kals Valley, East Tyrol.
Occurrence of Schallerite and Useful Mineral Association
Schallerite is commonly associated with ores such as willemite-franklinite, rhodonite. It occurs in a metamorphosed form of stratiform zinc deposit. It is also associated with calcite, tephroite, spessartine, rhodochrosite and pyroxmangite.
References