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| Vandenbrandeite | |
| Formula: | Cu(UO2)(OH)4 |
| Imasymbol: | Vbd[1] |
| Strunz: | 04.GB.45 |
| System: | Triclinic |
| Dana: | 05.03.02.01 |
| Class: | Triclinic-Pinacoidal |
| Symmetry: | P |
| Unit Cell: | 254.99 ų |
| Color: | Blackish green to dark green with bluish green tint |
| Cleavage: | Perfect on, Distinct and also indisctinct in the [001] zone |
| Fracture: | None |
| Tenacity: | Brittle |
| Mohs: | 4 |
| Luster: | Vitreous, sub-vitreous, greasy |
| Opticalprop: | Biaxial (-) |
| Refractive: | nα = 1.765 - 1.770 nβ = 1.780 - 1.792 nγ = 1.800 |
| Birefringence: | 0.035 |
| Pleochroism: | Visible |
| 2V: | Measured 90° Calculated 60°- 88° |
| Dispersion: | Visible to strong |
| Fluorescence: | None |
| Streak: | Green |
| Gravity: | 5.03 |
| Density: | 5.03 |
| Diaphaneity: | Transparent, translucent |
| Other: | Radioactive |
Vandenbrandeite is a mineral named after a belgian geologist, Pierre Van den Brande, who discovered an ore deposit. It was named in 1932, and has been a valid mineral ever since then.[2]
Vandenbrandeite grows in microcrystals, up to half a millimeter. It may be rounded, lathlike. The crystals are flattened on . It grows in parallel aggregates, in a lamellar, scaly shape.[3] It is tabular, meaning its dimensions in one direction are weak. It is a pleochroic mineral. Depending on the axis the mineral is seen the color of it changes, which is an optical phenomenon. On the x axis it can be seen as a blue-green, and on the z axis is seen as a yellow-green mineral. It is highly stable in the presence of both water and hydrogen peroxide. Vandenbrandeite, due to being strongly radioactive, is usually closely associated with other radioactive minerals.[4] Its radioactive properties is due to its composition. The mineral is made out of 59.27% uranium, which is the main component of the mineral. It has a GRapi (Gamma Ray American Petroleum Institute Units) of 4,352,567.33. It has a concentration of 229.75 measured in GRapi. Other chemical elements included in vandenbrandeite are oxygen (23.9%), copper (15.82%) and hydrogen (1%). Although it is radioactive, the mineral is not fluorescent. It is a secondary mineral. [5]