Jun 12 2014
Aeschynite-(Nd) was named because of its similarity to aeschynite-(Ce), with neodymium as the dominant rare-earth element. It is a part of the aeschynite group.
Properties of Aeschynite-(Nd)
The following are the key properties of Aeschynite-(Nd):
- Crystal Data
- Orthorhombic; metamict
- Point group: [2/m2/m2/m probable] [by analogy to aeschynite-(Ce)]
- Tabular and prismatic crystals, to several mm equi-granular and radiating clusters
- Massive
- X-ray powder pattern: 2.93 (10), 3.00 (9), 1.575 (7b), 1.95 (6), 1.53 (6b), 5.45 (5), 2.64 (5)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
| RE2O3 |
37.99 |
36.54 |
| Nb2O5 |
30.16 |
21.40 |
| TiO2 |
22.46 |
28.65 |
| CaO |
2.96 |
0.73 |
| ThO2 |
1.33 |
7.72 |
| Fe2O3 |
1.99 |
1.36 |
| H2O+ |
0.96 |
1.27 |
| SiO2 |
0.65 |
0.04 |
| Al2O3 |
0.54 |
0.64 |
| MgO |
0.44 |
0.35 |
| Na2O |
0.42 |
0.07 |
| U3O8 |
- |
0.06 |
| MnO |
0.06 |
trace |
| Ta2O5 |
0.04 |
1.24 |
| H2O- |
- |
0.10 |
| FeO |
- |
trace |
| K2O |
trace |
trace |
| Total |
100.00 |
100.17 |
- Optical Properties
- Semi-transparent
- Optical class: Isotropic to biaxial
- Pleochroism: Weak to distinct
- Orientation: X = a; Y = c; Z = b
- Dispersion: Weak to strong
- n = 2.1–2.4 (metamict)
- 2V(meas.) = 78°-82°
- Estimated Properties
| Electron density |
Bulk density (electron density) = 4.37 g/cm3
note: Specific gravity of Aeschynite-(Nd) = 4.82 g/cm3. |
| Photoelectric |
PEAeschynite-(Nd) = 241.66 barns/electron
U = PEAeschynite-(Nd) x ρ electron density = 1,054.85 barns/cm3 |
| Fermion index |
Fermion index = 0.08
Boson index = 0.92 |
Radioactivity
|
Aeschynite-(Nd) is radioactive
|
How to Identify Aeschynite-(Nd)
Aeschynite-(Nd) can be identified by its color, brown. Its sub-translucent form has no cleavage. This mineral has an adamantine luster, with a brown streak. The fracture on this mineral is brittle–conchoidal.
The density of aeschynite-(Nd) is 4.6 to 5.04 g/cm3, with a hardness of 5 to 6 - between apatite and orthoclase.
Global Distribution
Aeschynite-(Nd) is distributed mainly in China - from the Bayan Obo Fe–Nb–RE deposit, 130km north of Baotou, Inner Mongolia.
Occurrence of Aeschynite-(Nd) and Useful Mineral Association
Aeschynite-(Nd) occurs in the veins in slate and metamorphosed dolostone.
It is often associated with minerals such as aegirine, barite, fluorite, riebeckite, albite, magnetite, and phlogopite.
References