May 28 2014
Natrosilite is a monoclinic-prismatic mineral, containing sodium, silicon, and oxygen. It was first discovered in Mt. Karnasurt, Lovozero massif, and also in Khibiny massif, Kola Peninsula, Russia.
It was named for the natrium or sodium, oxygen and silicon in its composition.
Properties of Natrosilite
The following are the key properties of Natrosilite:
- Cell Data
- Space Group: P21/a
- a = 12.30(2)
- b = 4.88(1)
- c = 8.27(3)
- β = 104°14'
- Z = 4
- Crystal Data
- Monoclinic
- Point Group: 2/m
- Thick tabular pseudohexagonal crystals, to 6cm; granular
- X-ray Powder Pattern: 6.06 (10), 2.98 (9), 3.97 (8), 2.435 (8), 3.64 (7), 4.17 (6), 4.28 (5)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
| SiO2 |
66.03 |
65.97 |
| Na2O |
33.96 |
34.03 |
| K2O |
0.01 |
- |
| H2O- |
0.06 |
- |
| Total |
100.06 |
100.00 |
- Optical Properties
- Optical Class: Biaxial (-)
- Orientation: Y ^ c = -12° to 2°
- Dispersion: r < v
- α = 1.507
- β = 1.517
- γ = 1.521
- 2V(meas.) = 49°-64°
- Estimated Properties
| Electron density |
Bulk density (electron density) = 2.48 g/cm3
note: Specific gravity of Natrosilite = 2.51 g/cm3 |
| Photoelectric |
PENatrosilite = 1.58 barns/electron
U = PENatrosilite x ρElectron density = 3.92 barns/cm3 |
| Fermion index |
Fermion index = 0.01
Boson index = 0.99 |
Radioactivity
|
Natrosilite is not radioactive
|
How to Identify Natrosilite
Natrosilite can be either colorless or white. It has perfect cleavage, transparent appearance, and white streak.
The density of natrosilite is 2.48 g/cm3.
Global Distribution
Natrosilite is distributed in the following places:
- Mt. Karnasurt, Lovozero massif
- Khibiny massif, Kola Peninsula, Russia
- Mont Saint-Hilaire, Quebec, Canada
Occurrence of Natrosilite and Useful Mineral Association
Natrosilite occurs in sodalite xenoliths associated with an intrusive alkalic gabbro-syenite complex (Mont Saint-Hilaire, Canada), and in pegmatites in nepheline syenites in differentiated alkalic massifs (Kola Peninsula, Russia).
It is closely associated with revdite, eudialyte, cancrinite, sodalite, aegirine, aenigmatite, vuonnemite, ussingite, lomonosovite, natrolite, analcime, and microcline.
References