May 29 2014
Sarkinite is a dimorph of eveite, and a member of Wagnerite group. It was named after the Greek word for 'made of flesh', signifying its red color and greasy luster. The mineral was first observed as chondrarsenite in Sweden in 1865, and later identified as sarkinite in 1885.
Properties of Sarkinite
The following are the key properties of Sarkinite:
- Cell Data
- Space Group: P21/a
- a = 12.779(2)
- b = 13.596(2)
- c = 10.208(2)
- β = 108°53'
- Z = 16
- Crystal Data
- Monoclinic
- Point Group: 2/m
- Crystals: typically thick tabular {100}, elongated, to 4mm, short prismatic, or tabular along [010] May be crudely spherical, granular massive
- X-ray powder pattern: 3.18 (10), 3.04 (10), 3.29 (9), 3.48 (8), 2.90 (7), 2.65 (6), 6.0 (3)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
Content 3 |
| MnO |
51.6 |
51.77 |
53.38 |
| As2O5 |
41.6 |
44.09 |
43.23 |
| H2O |
3.06 |
[3.40] |
3.39 |
| CaO |
1.4 |
0.29 |
- |
| MgO |
0.98 |
0.19 |
- |
| CO2 |
0.76 |
- |
- |
| PbO |
0.25 |
- |
- |
| P2O5 |
0.21 |
- |
- |
| ZnO |
0.15 |
- |
- |
| FeO |
0.13 |
0.02 |
- |
| CuO |
- |
0.01 |
- |
| insol. |
0.38 |
- |
| Total |
100.37 |
[99.92] |
100 |
- Optical Properties
- Biaxial (–)
- Pleochroism: Weak
- Orientation: Y = b
- X ^ c = – 54°
- Dispersion: r < v
- Absorption: X > Z > Y
- α = 1.790–1.793
- β = 1.794–1.807
- γ = 1.798–1.809
- 2V(meas.) = 83°
- Estimated Properties
| Electron density |
Bulk density (electron density) = 2.98 g/cm3
note: Specific gravity of Sarkinite = 2.98 g/cm3 |
| Photoelectric |
PESarkinite = 2.61 barns/electron
U = PESarkinite x ρElectron density = 7.76 barns/cm3 |
| Fermion index |
Fermion index = 0.02
Boson index = 0.98 |
Radioactivity
|
Sarkinite is not radioactive
|
How to Identify Sarkinite
Sarkinite can be found in yellow, reddish-yellow, or dark red color. It has yellow streak, greasy luster, and distinct cleavage. The fractures are uneven, producing small, conchoidal fragments.
The relative hardness of sarkinite ranges from 4 to 5, and its average density is 4.13 g/cm3.
Global Distribution
Sarkinite is distributed in the following places:
- Harstigen mine, near Persberg, Sweden
- Brattfors mine, Sweden
- Langban, V¨armland
- Sj¨o mine, near Grythyttan, Orebro
- K¨odnitz Valley, Tirol, Austria
- Falotta mine, Oberhalbstein, Graub¨unden, Switzerland
- Sterling Hill, Ogdensburg
- Franklin, Sussex Co. New Jersey, USA
Occurrence of Sarkinite and Useful Mineral Association
Sarkinite occurs in metamorphosed Fe–Mn orebodies (Sweden), manganese-rich lenses in quartzitic chlorite schists, probably of marine origin (K¨odnitz Valley, Austria), and metamorphosed stratiform zinc orebodies (New Jersey, USA).
It is closely associated with manganese oxides, barite, rhodochrosite, serpierite, euchroite, copper, kraisslite, parabrandtite, brandtite, allactite, willemite, adamite, eveite, braunite, tilasite, manganoan berzeliite, grischunite, tiragalloite, spessartine, pyroxmangite, tephroite, jacobsite, magnetite, katoptrite, calcite, bementite, and lead.
References