Picromerite (synonyms: schoenite, schönite) is a mineral from the class of hydrous

sulfates The sulfate or sulphate ion is a Polyatomic ion, 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 salt (chemistry), ...

lacking additional anions, and containing medium to large cations according to the

Nickel–Strunz classification Nickel–Strunz classification is a scheme for categorizing minerals based upon their chemical composition, introduced by German mineralogist Karl Hugo Strunz (24 February 1910 – 19 April 2006) in his ''Mineralogische Tabellen'' (1941). The 4 ...

Etymology

The name comes from the Greek words πικρός ikrosfor "bitter" and μέρος

eros Eros (, ; ) is the Greek god of love and sex. The Romans referred to him as Cupid or Amor. In the earliest account, he is a primordial god, while in later accounts he is the child of Aphrodite. He is usually presented as a handsome young ma ...

for "part", and relates to the bitter taste of the mineral.

Occurrence

Picromerite is found on comparatively few places, currently (2015) only about 40 localities are known. It was first identified in active volcanic fumaroles on

Mount Vesuvius Mount Vesuvius ( ) is a Somma volcano, somma–stratovolcano located on the Gulf of Naples in Campania, Italy, about east of Naples and a short distance from the shore. It is one of several volcanoes forming the Campanian volcanic arc. Vesuv ...

Arcangelo Scacchi Arcangelo Scacchi (9 February 1810 – 11 October 1893) was an Italian physician, mineralogist, malacology, malacologist, and naturalist. He served as a professor of mineralogy at the University of Naples Federico II, University of Naples. Between ...

in 1855 and has also been found in volcanic deposits on

Mount Etna Mount Etna, or simply Etna ( or ; , or ; ; or ), is an active stratovolcano on the east coast of Sicily, Italy, in the Metropolitan City of Catania, between the cities of Messina, Italy, Messina and Catania. It is located above the Conve ...

and on

Hawai'i Hawaii ( ; ) is an island state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two non-contiguous U.S. states (along with Alaska), it is the only state not on the North American mainland, th ...

. It is more commonly found in the

kainite Kainite ( or ) (KMg(SO4)Cl·3H2O) is an evaporite mineral in the class of "Sulfates (selenates, etc.) with additional anions, with H2O" according to the Nickel–Strunz classification. It is a hydrated potassium-magnesium sulfate-chloride, natu ...

zones of some marine salt deposits, among them salt mines in

Thuringia Thuringia (; officially the Free State of Thuringia, ) is one of Germany, Germany's 16 States of Germany, states. With 2.1 million people, it is 12th-largest by population, and with 16,171 square kilometers, it is 11th-largest in area. Er ...

Lower Saxony Lower Saxony is a States of Germany, German state (') in Northern Germany, northwestern Germany. It is the second-largest state by land area, with , and fourth-largest in population (8 million in 2021) among the 16 ' of the Germany, Federal Re ...

and

Saxony-Anhalt Saxony-Anhalt ( ; ) is a States of Germany, state of Germany, bordering the states of Brandenburg, Saxony, Thuringia and Lower Saxony. It covers an area of and has a population of 2.17 million inhabitants, making it the List of German states ...

(Germany), near

Hall in Tirol Hall in Tirol is a town in the Innsbruck-Land district of Tyrol (state), Tyrol, Austria. Located at an altitude of 574 m, about 5 km (3 mi) east of the state's capital Innsbruck in the Inn (river), Inn valley, it has a population of 14,77 ...

Hallstatt Hallstatt () is a small town in the district of Gmunden District, Gmunden, in the Austrian state of Upper Austria. Situated between the southwestern shore of Hallstätter See and the steep slopes of the Dachstein massif, the town lies in the Sa ...

and

Bad Ischl Bad Ischl (Austrian German ) is a spa town in Austria. It lies in the southern part of Upper Austria, at the river Traun in the centre of the Salzkammergut region. The town consists of the Katastralgemeinden ''Ahorn'', ''Bad Ischl'', ''Haiden ...

(Austria), near

Whitby Whitby is a seaside town, port and civil parish in North Yorkshire, England. It is on the Yorkshire Coast at the mouth of the River Esk, North Yorkshire, River Esk and has a maritime, mineral and tourist economy. From the Middle Ages, Whitby ...

(UK), and in the Carlsbad Potash District (New Mexico), also on salt lakes in western

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. Picromerite can also form in sulfate-rich hydrothermal ore deposits and is found in slag heaps of some ore and coal mines. Picromerite is often accompanied by

anhydrite Anhydrite, or anhydrous calcium sulfate, is a mineral with the chemical formula CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the ...

epsomite Epsomite, Epsom salt, or magnesium sulfate heptahydrate, is a hydrous magnesium sulfate mineral with formula . Physical properties Epsomite crystallizes in the orthorhombic system. The normal form is as massive encrustations, while acicula ...

halite Halite ( ), commonly known as rock salt, is a type of salt, the mineral (natural) form of sodium chloride ( Na Cl). Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, pi ...

, hohmannite,

, metasideronatrite and metavoltine, depending on the locality.

Properties

Picromerite dehydrates in dry air, and crystals then show dull, spherical dehydration zones. Progressive dehydration leads to

leonite Leonite is a hydrated double sulfate of magnesium and potassium. It has the formula K2SO4·MgSO4·4H2O. The mineral was named after Leo Strippelmann, who was director of the salt works at Westeregeln in Germany. The mineral is part of the blodite ...

References

External links

* {{cite web , url = http://rruff.geo.arizona.edu/AMS/result.php?mineral=Picromerite , publisher = American Mineralogist Crystal Structure Database , title = Picromerite Potassium minerals Magnesium minerals Sulfate minerals Hexahydrate minerals Monoclinic minerals Minerals in space group 14 Evaporite