Jun 3 2014
Ershovite is a triclinic-pinacoidal mineral, containing titanium, sodium, silicon, potassium, oxygen, manganese, iron, and hydrogen.
It was named after Professor Vadim Victorovich Ershov of the Moscow Mining Institute in Moscow, Russia.
Properties of Ershovite
The following are the key properties of Ershovite:
- Cell Data
- Space Group: P1
- a = 10.244(2)
- b = 11.924(3)
- c = 5.276(3)
- α = 103:491(2)°
- β = 96:960(3)°
- γ = 91:945(3)°
- Z = 1
- Crystal Data
- Triclinic
- Point Group: 1
- Forms parallel, fibrous aggregates, fibers elongated along [001], to 3cm; in disseminated elongated grains, to 1cm
- X-ray Powder Pattern: 11.58 (10), 2.990 (10), 2.709 (8), 1.652 (8), 2.608 (7), 2.459 (6), 2.160 (6)
- Chemical Composition
| Elements |
Content |
| SiO2 |
47.1 |
| K2O |
13.6 |
| H2O |
[12.5] |
| Na2O |
12.4 |
| FeO |
6.1 |
| MnO |
4.7 |
| TiO2 |
3.0 |
| MgO |
0.5 |
| CaO |
0.1 |
| Total |
[100.0] |
- Optical Properties
- Optical Class: Biaxial (+)
- Pleochroism: Strong
- X = Y = light green or yellow; Z = dark olive-green
- Orientation: X ^ c = 86°; Y ^ c = 73°; Z ^ c = 17°
- Dispersion: r > v
- α = 1.569(2)
- β = 1.574(2)
- γ = 1.590(2)
- 2V(meas.) = 58(2)°
- 2V(calc.) = 59°
- Estimated Properties
| Electron density |
Bulk density (electron density) = 2.71 g/cm3
note: Specific gravity of Ershovite = 2.72 g/cm3 |
| Photoelectric |
PEErshovite = 4.83 barns/electron
U = PEErshovite x ρElectron density = 13.09 barns/cm3 |
| Fermion index |
Fermion index = 0.01
Boson index = 0.99 |
Radioactivity
|
Ershovite is barely detectable
|
How to Identify Ershovite
Ershovite occurs in a range of colors, from yellowish-green to brownish-green and olive-green. It has a transparent appearance, and forms fibrous crystals and anhedral grains. It is non-fluorescent, with perfect cleavage, vitreous luster, and white streak.
The average density of ershovite is 2.72 g/cm3, and its relative hardness ranges from 2.5 to 3.
Global Distribution
Ershovite is widely distributed in Mts. Rasvumchorr and Koashva, Khibiny massif, Kola Peninsula, Russia.
Occurrence of Ershovite and Useful Mineral Association
Ershovite occurs in unweathered, ultra-agpaitic pegmatites in a differentiated alkalic massif. It is closely associated with nacaphite, thermonatrite, koashvite, shcherbakovite, astrophyllite, vuonnemite, rasvumite, natrite, villiaumite, alkalic amphibole, aegirine, sodalite, nepheline, and orthoclase.
References