Jun 3 2014
Nanpingite belongs to the mica group of minerals. It was named after the Nanping area in China, where it is widely distributed.
Properties of Nanpingite
The following are the key properties of Nanpingite:
- Cell Data
- Space Group: C2/c
- a = 5.362(3)
- b = 8.86(1)
- c = 21.42(1)
- β = 95:77(2)°
- Z = 4
- Crystal Data
- Monoclinic
- Point Group: 2=m
- Rarely as pseudohexagonal crystals
- As radiating and comb aggregates
- Scales and plates, to 1cm
- X-ray powder pattern: 2.664 (100), 2.129 (85), 2.122 (16), 2.654 (14), 1.328 (14), 3.329 (6), 3.622 (5)
- Chemical Composition
| Elements |
Content 1 |
| SiO2 |
38.54 |
| Al2O3 |
25.61 |
| Cs2O |
25.29 |
| H2O |
3.27 |
| FeO |
2.44 |
| MgO |
1.78 |
| F |
1.00 |
| K2O |
0.54 |
| Li2O |
0.44 |
| -O = F2 |
0.42 |
| Rb2O |
0.25 |
| MnO |
0.07 |
| Total |
98.81 |
- Optical Properties
- Optical Class: Biaxial (-)
- Orientation: Z = b
- Dispersion: r > v; weak
- α = 1.551(5)
- β = 1.584 (2)
- γ = 1.588 (2)
- 2V (meas.) = 46 (2)°
- Estimated Properties
| Electron density |
Bulk density (electron density) = 2.96 g/cm3
note: Specific gravity of Nanpingite = 3.11 g/cm3 |
| Photoelectric |
PENanpingite = 99.89 barns/electron
U = PENanpingite x ρ electron density = 296.17 barns/cm3 |
| Fermion index |
Fermion index = 0.01
Boson index = 0.99 |
Radioactivity
|
Nanpingite is not radioactive
|
How to Identify Nanpingite
Nanpingite can be identified as a white or silver-white crystal, having a transparent to translucent appearance. The mineral is present in the form of well-formed, fine sized crystals with a glassy lustre, a white streak, and a perfect cleavage. The mineral exhibits brittle fractures, similar to that of non-metallic minerals and glasses. Its radial crystals radiate from the center without producing stellar patterns.
It has a density of 3.11 g/cm3, and a relative hardness ranging from 2.5 to 3.
Global Distribution
Nanpingite is distributed in the Nanping area, Fukien Province, China.
Occurrence of Nanpingite and Useful Mineral Association
Nanpingite occurs in the veinlets of a pollucite-rich middle zone of muscovite-albite-spodumene pegmatite, and in the Nanping pegmitite field, Yanping District, Nanping Prefecture, Fujian Province, China.
It is often associated with minerals such as apatite, quartz, and montebrasite.
References