May 16 2013
Mountainite is a transparent to translucent material named after Edgar Donald Mountain, Professor of Geology at Rhodes University, South Africa. It is a bright white fibrous acicular crystal aggregate with pale golden color.
Properties of Mountainite
The following are the key properties of mountainite:
Cell Data
- Space Group: n.d
- a = 13.51
- b = 6.55
- c = 13.51
- Z = 8
Crystal Data
- Monoclinic
- Point Group: n.d
- As matted laths and fibers forming small rosettes up to 2 mm.
- X-ray powder pattern: 2.94 (vvs), 6.6 (vs), 13.1 (s), 4.67 (s), 2.80 (ms), 1.967 (ms), 4.18 (m)
Chemical Composition
| Elements |
Content 1 |
Content 2 |
| SiO2 |
58.5 |
51.57 |
| Al2O3 |
0.0 |
2.31 |
| CaO |
13.4 |
20.07 |
| MgO |
0.2 |
0.0 |
| Na2O |
7.9 |
10.15 |
| K2O |
6.0 |
4.43 |
| H2O+ |
|
9.74 |
| H20- |
|
8.02 |
| H20 |
13.4 |
| CO2 |
|
0.87 |
| LOI |
|
2.47 |
| Total |
99.4 |
99.63 |
Optical Properties
- Optical Class: Biaxial +
- α= 1.500 – 1.504 β= 1.505 – 1.510 γ= 1.513 – 1.519
Estimated Properties
| |
|
| Electron density |
Bulk density (electron density)=2.36 g/cm3
note: Specific gravity of Helvine =2.34 g/cm3 |
| Photoelectric |
PEMountainite = 2.84 barns/electron
U=PEMountainite x ?electron= 6.70 barns/cc. |
| Fermion index |
Fermion Index = 0.01
Boson Index = 0.99 |
| Radioactivity |
Mountanite is not radioactive |
How to Identify Mountainite
Mountainite is transparent to translucent mineral, white and silky.
Global Distribution
Mountainite is distributed In the Bultfontein diamond mine, Kimberley, Cape Province, South Africa. It is also found on Mt. Karnasurt, Lovozero massif, Kola Peninsula, Russia and in the HÄowenegg quarry, Hegau, Baden-WÄurttemberg, Germany.
Occurrence of Mountainite and Useful Mineral Association
Mountainite was found in a kimberlite pipe (Kimberley, South Africa) and in a differentiated alkalic massif (Lovozero massif, Russia). It is associated with rhodesite, natrolite, chkalovite, neptunite, aegirine, leucosphenite, zorite, raite, polylithionite and halite.
References