| Becquerelite | |
| Category: | Oxide mineral |
| Formula: | Ca(UO2)6O4(OH)6·8(H2O) |
| Imasymbol: | Bqr[1] |
| Strunz: | 4.GB.10 |
| System: | Orthorhombic |
| Class: | Pyramidal (mm2) H-M symbol: (mm2) |
| Symmetry: | Pn21a |
| Unit Cell: | a = 13.8378 Å, b = 12.3781 Å, c = 14.9238 Å; Z = 4 |
| Colour: | Amber-yellow, golden to lemon-yellow, yellow-orange, brownish yellow |
| Habit: | Tabular prismatic striated crystals exhibiting pseudohexagonal outline; coatings and fine-grained aggregates |
| Cleavage: | Perfect on ; imperfect on, and |
| Tenacity: | Brittle |
| Mohs: | 2.5 |
| Lustre: | Adamantine to greasy |
| Streak: | Yellow |
| Diaphaneity: | Transparent |
| Gravity: | 5.09–5.2 |
| Opticalprop: | Biaxial (−) |
| Refractive: | nα = 1.725 – 1.735 nβ = 1.815 – 1.825 nγ = 1.825 – 1.830 |
| Birefringence: | δ = 0.100 |
| Pleochroism: | X = colourless to pale yellow, Y = Z = yellow to deep yellow |
| 2V: | Measured: 32° |
| Impurities: | Commonly contains lead |
| Other: | Radioactive |
| References: | [2] [3] [4] |
Becquerelite is a uranium mineral with the chemical formula: Ca(UO2)6O4(OH)6·8(H2O). It is a secondary mineral which contains calcium and is a bright yellow colour. It has a Mohs hardness of about 2.
It was named after the French physicist Antoine Henri Becquerel (1852–1908), who discovered radioactivity in 1896. Becquerelite contains about 70% uranium by weight.
It is mainly mined in Kasolo of the former Zaire, in the present day Democratic Republic of the Congo.