Zippeite is a hydrous

potassium Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmosph ...

uranium Uranium is a chemical element with the 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. Uranium is weak ...

sulfate The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many ...

mineral with formula: K₄( U O₂)₆( SO₄)₃(O H)₁₀·4( H₂O). It forms yellow to reddish brown

monoclinic In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in the orthorhombic s ...

-prismatic crystals with perfect cleavage. The typical form is as encrustations and pulverulent earthy masses. It forms as efflorescent encrustations in underground uranium mines. It has a

Mohs hardness The Mohs scale of mineral hardness () is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. The scale was introduced in 1812 by t ...

of 2 and a

specific gravity Relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water at its densest ...

of 3.66. It is strongly

fluorescent Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, ...

yellow under

ultraviolet light Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nanometer, nm (with a corresponding frequency around 30 Hertz, PHz) to 400 nm (750 Hertz, THz), shorter than that of visible light, but longer than ...

and is moderately

radioactive Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consi ...

Historical usage

A mineral which caught the attention of a Bohemian metallurgist, Adolf Patera, in the 1850s by its striking colour. It was named after the

Austria Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...

n mineralogist Franz Xaver Maximilian Zippe (1791–1863).Rösler, Hans Jürgen (1981) ''Lehrbuch der Mineralogie'' (''Manual of Mineralogy'') Deutscher Verlag für Grundstoffindustrie, Leipzig, page 418, , in German This was during the period when the fame of the Jachymov silver mines was dying out. On top of the large, forgotten pit-heaps, powdery minerals began to appear, vividly coloured, originating from the decomposition of the pitchblende. These colourful layers, in which zippeite was in the majority, gave

Patera In the material culture of classical antiquity, a ''phiale'' ( ) or ''patera'' () is a shallow ceramic or metal libation bowl. It often has a bulbous indentation (''omphalos'', "bellybutton") in the center underside to facilitate holding it, in ...

the idea of utilizing the uranium minerals in the manufacture of paints. Mining began in 1859 not only for the products which resulted from uraninite's decomposition, but for

uraninite Uraninite, formerly 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 causes ...

itself. A variety of yellow paints were manufactured because among all the secondary minerals on the pit-heap there was a prevalence of the yellow powdery coatings. Zippeite is one of the so-called 'uranium ochres'. It occurs in association with uranopilite, a monoclinic, complex water-soluble alkaline with other secondary uranium minerals in the weathered veins of uranium. Apart from Jachymov in Bohemia it occurs mainly near Wölsendorf in

Bavaria Bavaria ( ; ), officially the Free State of Bavaria (german: Freistaat Bayern, link=no ), is a state in the south-east of Germany. With an area of , Bavaria is the largest German state by land area, comprising roughly a fifth of the total lan ...

(

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

) and also in the US states of

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

and

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ke ...

. Zippeite is no longer used for the manufacture of paints, but is still used as a source of depleted uranium.

Notes

References

* Palache, C., H. Berman, and C. Frondel (1951) ''Dana’s System of Mineralogy,'' (7th edition), v. II, 598–599. *
Uranium minerals
{{Commons category Potassium minerals Sulfate minerals Uranium(VI) minerals Monoclinic minerals Minerals in space group 3

Historical usage

See also

Notes

References