Zippeite is a hydrous

potassium Potassium is a chemical element; it has Symbol (chemistry), symbol K (from Neo-Latin ) and atomic number19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to ...

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 ...

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 Vector (geometric), vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in t ...

-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 mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fair ...

of 2 and a

specific gravity Relative density, also called specific gravity, is a dimensionless quantity defined as the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for solids and liquids is nea ...

of 3.66. It is strongly

fluorescent Fluorescence is one of two kinds of photoluminescence, the emission of light by a substance that has absorbed light or other electromagnetic radiation. When exposed to ultraviolet radiation, many substances will glow (fluoresce) with color ...

yellow under

ultraviolet light Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of th ...

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 conside ...

Historical usage

A mineral which caught the attention of a

Bohemia Bohemia ( ; ; ) is the westernmost and largest historical region of the Czech Republic. In a narrow, geographic sense, it roughly encompasses the territories of present-day Czechia that fall within the Elbe River's drainage basin, but historic ...

n metallurgist, Adolf Patera, in the 1850s by its striking colour. It was named after the

Austria Austria, formally the Republic of Austria, is a landlocked country in Central Europe, lying in the Eastern Alps. It is a federation of nine Federal states of Austria, states, of which the capital Vienna is the List of largest cities in Aust ...

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 ''patera'' () or ''phiale'' ( ) is a shallow ceramic or metal libation bowl. It often has a bulbous indentation ('' omphalos'', "belly button") in the center underside to facilitate holding it, ...

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, 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 ...

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

it occurs mainly near Wölsendorf in

Bavaria Bavaria, officially the Free State of Bavaria, is a States of Germany, state in the southeast of Germany. With an area of , it is the list of German states by area, largest German state by land area, comprising approximately 1/5 of the total l ...

(

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

) and also in the US states of

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

and

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

. 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