Zippeite
Encyclopedia
Zippeite is a hydrous potassium
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...

 uranium
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...

 sulfate
Sulfate
In inorganic chemistry, a sulfate is a salt of sulfuric acid.-Chemical properties:...

 mineral with formula: K
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...

4(U
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...

O
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

2)6(S
Sulfur
Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...

O4)3(OH
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...

)10·4(H2O
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

). It forms yellow to reddish brown monoclinic-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 of 2 and a specific gravity
Specific gravity
Specific gravity is the ratio of the density of a substance to the density of a reference substance. Apparent specific gravity is the ratio of the weight of a volume of the substance to the weight of an equal volume of the reference substance. The reference substance is nearly always water for...

 of 3.66. It is strongly fluorescent yellow in UV radiation and is a radioactive mineral.

Historical usage

A mineral which caught the attention of a Bohemian
Bohemian
A Bohemian is a resident of the former Kingdom of Bohemia, either in a narrow sense as the region of Bohemia proper or in a wider meaning as the whole country, now known as the Czech Republic. The word "Bohemian" was used to denote the Czech people as well as the Czech language before the word...

 metallurgist, Adolf Patera
Adolf Patera
Adolf Patera , was a Bohemian chemist, mineralogist and metallurgist, best known for the important role he played in the utilisation of uranium in colour production in glass, and associated with silver extraction from the mines at Joachimsthal, then part of the Austro-Hungarian Empire, now known as...

 in the 1850s by its striking colour. This was during the period when the fame of the Jachymov
Jáchymov
For other places called Joachimsthal, see Joachimsthal Jáchymov . compl: "Sant Joachim's Sthal" is a spa town in north-west Bohemia in the Czech Republic belonging to the Karlovy Vary Region. It is situated at an altitude of 733 m above sea level in the eponymous St...

 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
Patera
A patera was a broad, shallow dish used for drinking, primarily in a ritual context such as a libation. These paterae were often used in Rome....

 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
Uraninite is a radioactive, uranium-rich mineral and ore with a chemical composition that is largely UO2, but also contains UO3 and oxides of lead, thorium, and rare earth elements...

 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. It was named after the Prague
Prague
Prague is the capital and largest city of the Czech Republic. Situated in the north-west of the country on the Vltava river, the city is home to about 1.3 million people, while its metropolitan area is estimated to have a population of over 2.3 million...

 mineralogist, F. X. M. Zippe (1791-1863). Apart from Jachymov in Bohemia
Bohemia
Bohemia is a historical region in central Europe, occupying the western two-thirds of the traditional Czech Lands. It is located in the contemporary Czech Republic with its capital in Prague...

 it occurs mainly near Wolsendorf in Bavaria
Bavaria
Bavaria, formally the Free State of Bavaria is a state of Germany, located in the southeast of Germany. With an area of , it is the largest state by area, forming almost 20% of the total land area of Germany...

 (Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

) and also in Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...

 (U.S.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

). Zippeite is no longer used for the manufacture of paints. It is used as a uranium ore, as is pitchblende.
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