May 20 2014
Chaidamuite was named after the place of its occurrence, near Chaidamu in China.
Properties of Chaidamuite
The following are the key properties of chaidamuite:
- Cell Data
- Space group: P1
- a = 7.309(2)
- b = 7.202(2)
- c = 9.691(3)
- α = 89.64(3)°
- β = 105.89(3)°
- γ = 91.11(2)°
- Z = 2
- Crystal Data
- Triclinic, pseudomonoclinic
- Point group: 1
- As thick tabular to pseudocubic crystals, with {001}, {010}, {011}, and {101}
- As grains or granular aggregates, to < 1mm
- X-ray powder pattern: 3.118 (100), 3.090 (95), 9.40 (80), 5.00 (80), 3.64 (70), 5.03 (65), 2.048 (40)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
| SO3 |
40.63 |
39.79 |
| Fe2O3 |
20.00 |
19.84 |
| H2O |
19.21 |
20.15 |
| ZnO |
17.00 |
20.22 |
| FeO |
2.09 |
- |
| SiO2 |
0.15 |
- |
| Al2O3 |
0.12 |
- |
| MnO |
0.06 |
- |
| Na2O |
0.02 |
- |
| K2O |
0.01 |
- |
| Total |
99.29 |
100.00 |
- Optical Properties
- Optical class: Biaxial (+)
- Pleochroism: Strong; X = pale yellow to colorless; Y = pale yellow; Z = brownish-yellow
- Orientation: X = b; Y ^ a = 12°; Z ^ c = 28°
- Dispersion: r < v, strong
- α = 1.632(1); β = 1.640(1); γ = 1.688(1)
- 2V(meas.) = 44(2)°
- Estimated Properties
| Electron density |
Bulk density (electron density) = 2.72 g/cm3
note: Specific gravity of chaidamuite = 2.72 g/cm3 |
| Photoelectric |
PE chaidamuite = 12.86 barns/electron
U=PE chaidamuite x ρ electron density = 34.96 barns/cm3 |
| Fermion index |
Fermion index = 0.01
Boson index = 0.99 |
Radioactivity
|
Chaidamuite is not radioactive
|
How to Identify Chaidamuite
Chaidamuite can be identified in the field by its color variations, such as brown and yellowish-brown. Its translucentform has {001} perfect and {100} perfect cleavage. This mineral has a vitreous luster, with light yellow streak.
The density of chaidamuite is 2.722 g/cm3 with a hardness of 2.5 to 3 - between finger nail and calcite. It is non-fluorescent.
Global Distribution
Chaidamuite is distributed mainly in the Xitieshan Pb–Zn mine, south of Mt. Qilianshan, Chaidamu, Qinghai Province, China.
Occurrence of Chaidamuite and Useful Mineral Association
Chaidamuite occurs in a secondary mineral in the oxidized portions of a Pb–Zn–Fe sulfide deposit.
It is often associated with minerals such as coquimbite, copiapite, butlerite, and zincobotryogen.
References