Plášilite is a very rare

uranium Uranium is a chemical element; it has chemical symbol, symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Ura ...

mineral with the formula Na₂(UO₂)(SO₄)₂•3H₂O. Chemically related minerals include natrozippeite, belakovskiite, meisserite,

fermiite Fermiite is a rare uranium mineral with the formula Na4(UO2)(SO4)3·3H2O.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 mi ...

and oppenheimerite. Most of these

uranyl The uranyl ion with the chemical formula has a linear structure with short U–O bonds, indicative of the presence of multiple bonds between uranium and oxygen, with uranium in the oxidation state +6. Four or more ligands may be bound to the u ...

sulfate mineral The sulfate minerals are a class of minerals that include the sulfate ion () within their structure. The sulfate minerals occur commonly in primary evaporite depositional environments, as gangue minerals in hydrothermal Vein (geology), veins and as ...

s were originally found in the Blue Lizard mine, San Juan County, Utah, US. The mineral is named after Czech crystallographer Jakub Plášil.

Association and origin

Plášilite is associated with other sulfate minerals: natrozippeite, johannite,

blödite Blödite or bloedite is a hydrated sodium magnesium sulfate mineral with the formula Na2Mg(SO4)2·4H2O. The mineral is clear to yellow in color often darkened by inclusions and forms monoclinic crystals. Blödite was first described in 1821 for ...

brochantite Brochantite is a sulfate mineral, one of a number of cupric sulfates. Its chemical formula is Cu4SO4(OH)6. Formed in arid climates or in rapidly oxidizing copper sulfide deposits, it was named by Armand Lévy (mineralogist), Armand Lévy for his ...

chalcanthite Chalcanthite (, ) is a richly colored blue-green water-soluble sulfate mineral . It is commonly found in the late-stage oxidation zones of copper deposits. Due to its ready solubility, chalcanthite is more common in arid regions. Chalcanthite i ...

gypsum Gypsum is a soft sulfate mineral composed of calcium sulfate Hydrate, dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, drywall and blackboard or sidewalk ...

hexahydrite Magnesium sulfate or magnesium sulphate is a chemical compound, a salt with the formula , consisting of magnesium cations (20.19% by mass) and sulfate anions . It is a white crystalline solid, soluble in water but not in ethanol. Magnesium su ...

manganoblödite Manganoblödite is a rare manganese mineral with the formula Na2Mn(SO4)2·4H2O. Somewhat chemically similar mineral is D'Ansite-(Mn). Manganoblödite was found in the Blue Lizard mine, San Juan County, Utah, US, which is known for several relativ ...

, and tamarugite. Non-sulfate coexisting minerals include

atacamite Atacamite is a copper halide mineral: a copper(II) chloride hydroxide with formula Cu2Cl(OH)3. It was first described for deposits in the Atacama Desert of Chile in 1802 by Dmitri de Gallitzin. The Atacama Desert is also the namesake of the min ...

calcite Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...

dickite Dickite () is a phyllosilicate clay mineral named after the metallurgical chemist Allan Brugh Dick, who first described it. It is chemically composed of 20.90% aluminium, 21.76% silicon, 1.56% hydrogen and 55.78% oxygen. It has the same composit ...

and

gerhardtite Copper(II) nitrate describes any member of the family of inorganic compounds with the formula Copper, Cu(Nitrate, NO3)2(H2O)x. The hydrates are hygroscopic blue solids. Anhydrous copper nitrate forms blue-green crystals and Sublimation (phase tr ...

. Plášilite is secondary in origin, being the product of weathering of the primary uranium mineral,

uraninite Uraninite, also known as pitchblende, is a radioactive, uranium-rich mineral and ore with a chemical composition that is largely UO2 but because of oxidation typically contains variable proportions of U3O8. Radioactive decay of the uranium c ...

Crystal structure

The crystal structure of plášilite is of a new type. Its building blocks are: * (UO₂)₂(SO₄)₂(OH)₂ sheets, with a charge 2-, parallel to (010), of a phosphuranylite topology * edge-sharing NaO₂(H₂O)₄ polyhedra, parallel to 01The sodium-bearing polyhedra link the uranyl-sulfate sheets. It terms of sheet geometry, crystal structure of plášilite is similar to that of deliensite.

References

Uranium(VI) minerals Sulfate minerals Sodium minerals Monoclinic minerals Minerals in space group 14 {{sulfate-mineral-stub