Chemistry:Fermiite
| Fermiite | |
|---|---|
| General | |
| Category | Sulfate mineral |
| Formula (repeating unit) | Na4(UO2)(SO4)3·3H2O |
| Crystal system | Orthorhombic |
| Crystal class | Pyramidal (mm2) H-M symbol: (mm2) |
| Space group | Pmn21 |
| Unit cell | a = 11.84, b = 7.87 c = 15.33 [Å] (approximated); Z = 4 |
| Identification | |
| Color | Pale greenish-yellow |
| Crystal habit | prismatic |
| Cleavage | None |
| Tenacity | Brittle |
| Mohs scale hardness | 2.5 |
| Streak | White |
| Diaphaneity | Transparent |
| Density | 3.31 (calculated); 3.23 (measured) |
| Optical properties | Biaxal (+) |
| Refractive index | nα=1.52, nβ=1.53, nγ=1.57 (approximated) |
| Pleochroism | Colourless (X & Y), pale greenish-yellow (Z) |
| 2V angle | 50o (calculated) |
| Other characteristics |  Radioactive |
| References | [1][2] |
Fermiite is a rare uranium mineral with the formula Na4(UO2)(SO4)3·3H2O.[4] Chemically related minerals include oppenheimerite, meisserite (which is also structurally-related to fermiite),[2] belakovskiite, natrozippeite and plášilite.[5][6][7][8][9] Fermiite comes from the Blue Lizard mine, San Juan County, Utah, USA, which is known for many rare uranium minerals.[1][2][10] The name honors Enrico Fermi (1901–1954).[2]
Association
Fermiite is closely associated with numerous other sulfate minerals: oppenheimerite, bluelizardite, wetherillite, blödite, manganoblödite, chalcanthite, epsomite, gypsum, hexahydrite, kröhnkite, sideronatrite and tamarugite.[4]
Crystal structure
The main building block of the crystal structure of fermiite is a chain of the composition (UO2)(SO4)3. Chains are connected with five types of Na-O polyhedra.[4]
References
- ↑ 1.0 1.1 Kampf, A.R., Plášil, J., Kasatkin, A.V., Marty, J., and Čejka, J., 2015. Fermiite, Na4(UO2)(SO4)3·3H2O and oppenheimerite, Na2(UO2)(SO4)2·3H2O, two new uranyl sulfate minerals from the Blue Lizard mine, San Juan County, Utah, USA. Mineralogical Magazine 79(5), 1123-1142
- ↑ 2.0 2.1 2.2 2.3 "Fermiite: Fermiite mineral information and data". http://www.mindat.org/min-46506.html. Retrieved 2016-03-04.
- ↑ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine 85 (3): 291–320. doi:10.1180/mgm.2021.43. Bibcode: 2021MinM...85..291W.
- ↑ 4.0 4.1 4.2 Kampf, A.R., Plášil, J., Kasatkin, A.V., Marty, J., and Čejka, J., 2015. Fermiite, Na4(UO2)(SO4)3·3H2O and oppenheimerite, Na2(UO2)(SO4)2·3H2O, two new uranyl sulfate minerals from the Blue Lizard mine, San Juan County, Utah, USA. Mineralogical Magazine 79(5), 1123-1142
- ↑ "Oppenheimerite: Oppenheimerite mineral information and data". http://www.mindat.org/min-46514.html. Retrieved 2016-03-10.
- ↑ "Meisserite: Meisserite mineral information and data". http://www.mindat.org/min-43905.html. Retrieved 2016-03-10.
- ↑ "Belakovskiite: Belakovskiite mineral information and data". http://www.mindat.org/min-45960.html. Retrieved 2016-03-10.
- ↑ "Natrozippeite: Natrozippeite mineral information and data". http://www.mindat.org/min-3694.html. Retrieved 2016-03-10.
- ↑ "Plášilite: Plášilite mineral information and data". http://www.mindat.org/min-46145.html. Retrieved 2016-03-10.
- ↑ "Blue Lizard Mine, Chocolate Drop, Red Canyon, White Canyon District, San Juan Co., Utah, USA - Mindat.org". http://www.mindat.org/loc-38665.html. Retrieved 2016-03-04.
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