May 9 2013
Sengierite is a monoclinic-prismatic mineral containing oxygen, copper, hydrogen, uranium, and vanadium.
The mineral was named after Edgard Sengier (1879–1963), the Director of Union Mini`ere du Haut Katanga, which was the chief mining company in the former Belgian Congo.
Properties of Sengierite
The following are the key properties of sengierite:
- Cell Data
- Space group: P21/a
- a = 10.599(5)
- b = 8.093(4)
- c = 10.085(9)
- β = 103.42(6)°
- Z = 2
- Crystal Data
- Monoclinic
- Point group: 2/m
- Crystals are six-sided thin plates, flattened on {001}, to 2 mm, showing {001}, {110}, {100}, {201}, {111}; as flaky coatings
- X-ray powder pattern: 9.82 (vvs), 4.91 (vs), 3.735 (s), 3.197 (s), 3.179 (s), 3.144 (s), 3.094 (s)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
| UO3 |
47.45 |
55.05 |
| V2O5 |
15.96 |
17.50 |
| CuO |
14.82 |
15.31 |
| H2O |
15.77 |
12.14 |
| (Fe, Al)2O3 |
1.43 |
- |
| Total |
95.43 |
100.00 |
- Optical Properties
- Optical class: Biaxial (–)
- Pleochroism: X = bluish green to colorless; Y = olive-green
- to greenish yellow; Z = yellowish green to colorless
- Orientation: Y = b; X ^ c = 13 °40’
- Dispersion: r < v, strong
- Absorption: Z = Y > X
- α = 1.76–1.77
- β = 1.92–1.94
- γ = 1.94–1.97
- 2V(meas.) = 37°–39°
- Estimated Properties
| Electron density |
Bulk density (electron density)= 3.58 g/cm3
note: Specific gravity of sengierite = 4.05 g/cm3 |
| Photoelectric |
PESengierite = 1,224.44 barns/electron
U=PESengierite x ρelectron density= 4,381.14 barns/cm3 |
| Fermion index |
Fermion index = 0.0038029122
Boson index = 0.9961970878 |
Radioactivity
|
GRapi = 3,566,751.97 (Gamma Ray American Petroleum Institute Units)
Sengierite is radioactive |
How to Identify Sengierite
Sengierite can be identified in the field by its green or yellow green color variations. The appearance of this mineral is transparent. It is a mineral with a vitreous-adamantine luster, cleavages, and a light green streak. The fractures in the mineral are brittle, and the crystals are blocky and prismatic. The density of sengierite is 4.05 g/cm3 and hardness is 2.5 approximate to a finger nail.
Global Distribution
Sengierite is widely distributed in the following locations:
- Congo - From the Luiswishi copper mine, Lubumbashi; at Shinkolobwe and in the Ruiwe, Musonoi, and Mutoshi mines, Katanga Province
- USA - From the Cole shaft, Bisbee, Cochise Co., Arizona, and the Section 33 mine, Grants district, McKinley Co., New Mexico
- Argentina - In the Malarg¨ue district, Mendoza Province
- Czech Republic - Bohemia, Hradec Králové Region, Rozmital
- Germany - Baden-Württemberg, Black Forest, Rankach valley, Clara Mine
- France - At the Rab´ejac uranium deposit, seven km south-southeast of Lod`eve, H´erault
- Morocco - From the Argana Bigoudine area, Amelal.
Occurrence of Sengierite and Useful Mineral Association
Sengierite is often associated with minerals such as vandenbrandeite, chrysocolla, vlborthite, malachite, cobalt oxides (Luiswishi mine, Congo); covellite, malachite, chalcocite, tyuyamunite, chlorargyrite (Cole shaft, Arizona, USA).
Sengierite occurs as a rare secondary mineral, deposited from solutions derived from primary uraninite.
References