Aug 29 2013
Davreuxite is a monoclinic-prismatic mineral containing silicon, oxygen, manganese, hydrogen, and aluminum. The mineral was first discovered in the Stavelot massif, Belgium. It was named after Charles Joseph Davreux, Professor of Mineralogy at the University of Liµege, Belgium.
Properties of Davreuxite
The following are the key properties of Davreuxite:
- Cell Data
- Space Group: P21/m
- a = 9.518(6)
- b = 5.753(2)
- c = 12.04(1)
- β = 108:00(5)°
- Z = 2
- Crystal Data
- Monoclinic
- Point Group: 2 = m
- Asbestiform; as small bundles of extremely fine fibers, to several cm; these may be folded or imbricated
- X-ray Powder Pattern - 3.511 (100), 2.870 (60), 3.103 (45), 4.290 (40), 5.719 (35), 2.840 (35), 8.51 (30).
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
Content 3 |
| Al2O3 |
46.88 |
48.09 |
48.15 |
| SiO2 |
37.82 |
37.45 |
37.84 |
| MnO |
9.08 |
9.14 |
11.17 |
| H2O |
2.83 |
2.82 |
2.84 |
| Fe2O3 |
1.10 |
- |
- |
| CuO |
0.79 |
- |
- |
| ZnO |
0.49 |
- |
- |
| MgO |
0.44 |
0.45 |
- |
| P2O5 |
0.35 |
- |
- |
| FeO |
- |
1.29 |
- |
| Cr2O3 |
- |
trace |
- |
| TiO2 |
- |
trace |
- |
| Total |
99.78 |
99.24 |
100.00 |
- Optical Properties
- Optical Class: Biaxial (-)
- Orientation: Z = b
- X ≈ ⊥ {100}
- α = 1.660(5)
- β = 1.684(2)
- γ = 1.690(2)
- 2V(meas.) = 48°-70°.
- Estimated Properties
| Electron density |
Bulk density (electron density)=3.10 g/cm3
note: Specific gravity of Davreuxite =3.15 g/cm3 |
| Photoelectric |
PEDavreuxite = 3.60 barns/electron
U= PEDavreuxite x ρElectron density= 11.19 barns/cm3 |
| Fermion index |
Fermion index = 0.008
Boson index = 0.992 |
|
Radioactivity
|
Davreuxite is not radioactive. |
How to Identify Davreuxite
Davreuxite is a creamy white or light pink color mineral with a white streak and silky luster. It has brittle fractures as shown in glasses and most of the non-metallic minerals. The density of davreuxite is 3.15 g/cm3 and its hardness ranges from 2 to 3.
Global Distribution
Davreuxite is distributed Stavelot massif, at Ottre, Sart-Close, Regne, Recht and near Salmchateau in Belgium.
Occurrence of Davreuxite and Useful Mineral Association
Davreuxite occurs in quartz veins cutting Mn, Al-rich metapelites derived from shales subjected to low-grade metamorphism. The minerals that are closely associated with davreuxite include chlorite, hematite, chloritoid, dickite, rutile, kaolinite, sudoite, andalusite, ottrelite, pyrophyllite and quartz.
References