Aug 15 2013
Microsommite was named after the place, Monte Somma, Italy where it is widely distributed and also after a Greek word for 'small'. It is a member of Cancrinite group of minerals.
Properties of Microsommite
The following are the key properties of Microsommite:
- Cell Data
- Space Group: P6322
- a = 22.08(4)
- c = 5.33(2)
- Z = 3.
- Crystal Data
- Hexagonal
- Point Group: 622
- As groups of minute prismatic crystals, striated their length.
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
| Al2O3 |
32.07 |
31.57 |
| SiO2 |
31.70 |
30.74 |
| CaO |
14.72 |
10.77 |
| Na2O |
12.45 |
8.46 |
| Cl |
6.99 |
7.65 |
| K2O |
4.27 |
8.97 |
| SO3 |
- |
5.17 |
| -O = Cl2 |
1.58 |
1.73 |
| Total |
100.62 |
101.60 |
- Optical Properties
- Optical Class: Uniaxial (+)
- ω = 1.521
- ε = 1.529.
- Estimated Properties
| Electron density |
Bulk density (electron density) = 2.38 g/cm3
note: Specific gravity of Microsommite = 2.41 g/cm3 |
| Photoelectric |
PEMicrosommite = 3.32 barns/electron
U = PEMicrosommite x ρElectron = 7.88 barns/cm3 |
| Fermion index |
Fermion index = 0.007
Boson index = 0.992 |
| Radioactivity |
Estimated Radioactivity from Microsommite - barely detectable. |
How to Identify Microsommite
Microsommite is present in white and colourless crystal forms. The mineral has a transparent appearance. It has a silky lustre, a white streak and perfect cleavage. The crystals are well-formed with parallel lines on a crystal surface or a cleavage face. The relative hardness of the mineral is 6, and its density ranges from 2.42 to 2.53 g/cm3.
Global Distribution
Microsommite is widely distributed in the following locations:
- Monte Somma, Campania
- Pitigliano, near Grosseto, Tuscany, Italy.
Occurrence of Microsommite and Useful Mineral Association
Microsommite occurs in leucitites and ejected volcanic masses. It is closely associated with nepheline.
References