Belakovskiite

Belakovskiite
General
Category Sulfate mineral
Formula
(repeating unit)		 Na7(UO2)(SO4)4(SO3OH)(H2O)3
Crystal system Triclinic, P1
Unit cell a=5.46, b=11.33, c=18.42 [Å], α=104.77o, β=90.09o, γ=96.77o (approximated)
Identification
Color Yellow-green
Crystal habit fibrous
Crystal symmetry Triclinic - Pinacoidal (1)
Cleavage None
Tenacity Brittle
Mohs scale hardness ca. 2 (probable)
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 [1][2][3]

Belakovskiite is a very rare uranium mineral with the formula Na7(UO2)(SO4)4(SO3OH)(H2O)3.[1][2] It is interesting in being a natural uranyl salt with hydrosulfate anion, a feature shared with meisserite.[4] Other chemically related minerals include fermiite, oppenheimerite, natrozippeite and plášilite.[5][6][7][8] Most of these uranyl sulphate minerals was originally found in the Blue Lizard mine, San Juan County, Utah, US.[9] The mineral is named after Russian mineralogist Dmitry Ilych Belakovskiy.[1]

Association

Belakovskiite is associated with other sulfate minerals: meisserite, blödite, ferrinatrite, kröhnkite, and metavoltine.[1]This association is found as efflorescences on a sandstone associated with uranium mineralization.[3]

Crystal structure

The framework of belakovskiite is unique. The main building block of its crystal structure is a hexavalent cluster with composition (UO2)(SO4)4(H2O). Such clusters are connected via Na-O and hydrogen bonds.[1]

References

  1. 1 2 3 4 5 Kampf, A.R., Plášil, J., Kasatkin, A.V., and Marty, J., 2014. Belakovskiite, Na7(UO2)(SO4)4(SO3OH)(H2O)3, a new uranyl sulfate mineral from the Blue Lizard mine, San Juan County, Utah, USA. Mineralogical Magazine 78(3), 639-649
  2. 1 2 "Belakovskiite: Belakovskiite mineral information and data". Mindat.org. Retrieved 2016-03-10.
  3. 1 2 "Belakovskiite - Handbook of Mineralogy" (PDF). Handbookofmineralogy.org. Retrieved 2016-03-10.
  4. ↑ "Meisserite: Meisserite mineral information and data". Mindat.org. Retrieved 2016-03-10.
  5. ↑ "Fermiite: Fermiite mineral information and data". Mindat.org. Retrieved 2016-03-10.
  6. ↑ "Oppenheimerite: Oppenheimerite mineral information and data". Mindat.org. Retrieved 2016-03-10.
  7. ↑ "Natrozippeite: Natrozippeite mineral information and data". Mindat.org. Retrieved 2016-03-10.
  8. ↑ "Plášilite: Plášilite mineral information and data". Mindat.org. Retrieved 2016-03-10.
  9. ↑ "Blue Lizard Mine, Chocolate Drop, Red Canyon, White Canyon District, San Juan Co., Utah, USA - Mindat.org". Mindat.org. Retrieved 2016-03-10.
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