Belakovskiite
Very rare uranium mineral
From Wikipedia, the free encyclopedia
Belakovskiite is a very rare uranium mineral with the formula Na7(UO2)(SO4)4(SO3OH)(H2O)3.[2][3] It is interesting in being a natural uranyl salt with hydrosulfate anion, a feature shared with meisserite.[5] Other chemically related minerals include fermiite, oppenheimerite, natrozippeite and plášilite.[6][7][8][9] Most of these uranyl sulfate minerals was originally found in the Blue Lizard mine, San Juan County, Utah, US.[10] The mineral is named after Russian mineralogist Dmitry Ilych Belakovskiy.[2]
| Belakovskiite | |
|---|---|
| General | |
| Category | Sulfate mineral |
| Formula | Na7(UO2)(SO4)4(SO3OH)(H2O)3 |
| IMA symbol | Bkk[1] |
| Crystal system | Triclinic |
| Crystal class | Pinacoidal (1) (same H-M symbol) |
| Space group | P1 |
| Unit cell | a = 5.46, b = 11.33, c = 18.42 [Å], α = 104.77°, β = 90.09°, γ = 96.77° (approximated); Z = 2 |
| Identification | |
| Color | Yellow-green |
| Crystal habit | fibrous |
| Cleavage | None |
| Tenacity | Brittle |
| Mohs scale hardness | 2 |
| Luster | Vitreous |
| Streak | White |
| Diaphaneity | Transparent |
| Density | 3.31 (calculated); 3.23 (measured) |
| Optical properties | Biaxal (+) |
| Refractive index | nα=1.50, nβ=1.51, nγ=1.52 (approximated) |
| Pleochroism | None |
| 2V angle | 88o (calculated) |
| Other characteristics |  Radioactive |
| References | [2][3][4] |
Association
Crystal structure
The framework of belakovskiite crystal structure is a hexavalent cluster with composition (UO2)(SO4)4(H2O). Such clusters are connected via Na-O and hydrogen bonds.[2]