Periclase is a

magnesium Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 ...

mineral that occurs naturally in contact

metamorphic rock Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock ( protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, caus ...

s and is a major component of most basic

refractory In materials science, a refractory (or refractory material) is a material that is resistant to decomposition by heat or chemical attack and that retains its strength and rigidity at high temperatures. They are inorganic, non-metallic compound ...

bricks. It is a

cubic Cubic may refer to: Science and mathematics * Cube (algebra), "cubic" measurement * Cube, a three-dimensional solid object bounded by six square faces, facets or sides, with three meeting at each vertex ** Cubic crystal system, a crystal system w ...

form of

magnesium oxide Magnesium oxide (MgO), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of MgO and consists of a lattice of Mg2+ ions and O2− ions ...

( Mg O). In nature it usually forms a

solid solution A solid solution, a term popularly used for metals, is a homogeneous mixture of two compounds in solid state and having a single crystal structure. Many examples can be found in metallurgy, geology, and solid-state chemistry. The word "solutio ...

with

wüstite Wüstite ( Fe O, sometimes also written as Fe0.95O) is a mineral form of mostly iron(II) oxide found with meteorites and native iron. It has a grey colour with a greenish tint in reflected light. Wüstite crystallizes in the isometric-hexoc ...

(FeO) and is then referred to as ferropericlase or magnesiowüstite. It was first described in 1840 and named from the Greek περικλάω (to break around) in allusion to its cleavage. The type locality is

Monte Somma Mount Somma () is a mountain located in the Province of Naples, in the Campania region of southern Italy. It is high. It is an integral part of the Somma–Vesuvius volcanic complex and of the larger Campanian volcanic arc, which is known for it ...

, Somma-

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 ...

Complex, Naples Province,

Campania Campania is an administrative Regions of Italy, region of Italy located in Southern Italy; most of it is in the south-western portion of the Italian Peninsula (with the Tyrrhenian Sea to its west), but it also includes the small Phlegraean Islan ...

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

. The old term for the mineral is ''magnesia''. Stones from the Magnesia region in ancient

Anatolia Anatolia (), also known as Asia Minor, is a peninsula in West Asia that makes up the majority of the land area of Turkey. It is the westernmost protrusion of Asia and is geographically bounded by the Mediterranean Sea to the south, the Aegean ...

contained both magnesium oxide and hydrated

magnesium carbonate Magnesium carbonate, (archaic name magnesia alba), is an inorganic salt that is a colourless or white solid. Several hydrated and Base (chemistry), basic forms of magnesium carbonate also exist as minerals. Forms The most common magnesium car ...

as well as

iron oxide An iron oxide is a chemical compound composed of iron and oxygen. Several iron oxides are recognized. Often they are non-stoichiometric. Ferric oxyhydroxides are a related class of compounds, perhaps the best known of which is rust. Iron ...

s (such as

magnetite Magnetite is a mineral and one of the main iron ores, with the chemical formula . It is one of the iron oxide, oxides of iron, and is ferrimagnetism, ferrimagnetic; it is attracted to a magnet and can be magnetization, magnetized to become a ...

). Thus these stones, called ''Stones from Magnesia'' in antiquity, with their unusual magnetic properties were the reason the terms ''

magnet A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, ...

'' and ''

magnetism Magnetism is the class of physical attributes that occur through a magnetic field, which allows objects to attract or repel each other. Because both electric currents and magnetic moments of elementary particles give rise to a magnetic field, ...

'' were coined. Periclase is usually found in

marble Marble is a metamorphic rock consisting of carbonate minerals (most commonly calcite (CaCO3) or Dolomite (mineral), dolomite (CaMg(CO3)2) that have recrystallized under the influence of heat and pressure. It has a crystalline texture, and is ty ...

produced by

metamorphism Metamorphism is the transformation of existing Rock (geology), rock (the protolith) to rock with a different mineral composition or Texture (geology), texture. Metamorphism takes place at temperatures in excess of , and often also at elevated ...

of dolomitic

limestones Limestone is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Limestone forms when these ...

. It readily alters to

brucite Brucite is the mineral form of magnesium hydroxide, with the chemical formula Magnesium, Mg(hydroxyl, OH)2. It is a common alteration product of periclase in marble; a low-temperature hydrothermal Vein (geology), vein mineral in metamorphosed li ...

under near surface conditions. In addition to its type locality, it is reported from

Predazzo Predazzo (, literally big meadow) is a village and ''comune'' in the province of Trento, northern Italy. Predazzo is located about 58 kilometres northeast of Trento in Val di Fiemme. It is one of the main centers of Val di Fiemme (the other is C ...

Trentino Trentino (), officially the Autonomous Province of Trento (; ; ), is an Autonomous province#Italy, autonomous province of Italy in the Northern Italy, country's far north. Trentino and South Tyrol constitute the Regions of Italy, region of Tren ...

;

Carlingford, County Louth Carlingford (; ) is a coastal town and civil parish in northern County Louth, Ireland. For the purposes of local government, the town is part of the Dundalk Municipal District. It is situated on the southern shore of Carlingford Lough with S ...

, Ireland;

Broadford, Skye Broadford ( ), together with nearby Harrapool, is the second-largest settlement on the Isle of Skye, Scotland. Lying in the shadow of the Red Cuillin mountains, Broadford is within the parish of Strath. A long meandering village historically c ...

and the island of Muck, Scotland; León, Spain; the Bellerberg Volcano,

Eifel The Eifel (; , ) is a low mountain range in western Germany, eastern Belgium and northern Luxembourg. It occupies parts of southwestern North Rhine-Westphalia, northwestern Rhineland-Palatinate and the southern area of the German-speaking Com ...

district, Germany;

Nordmark The Northern March or North March (, ) was created out of the division of the vast ''Marca Geronis'' in 965. It initially comprised the northern third of the ''Marca'' (roughly corresponding to the modern state of Brandenburg) and was part of the ...

and

Långban Långban is a mining area in Värmland in Sweden. It belongs to Filipstad Municipality, with the nearest city being Filipstad, 21 km south. It was systematically mined through 1711–1972, but has traces from the 15th century. It is the birt ...

, Varmland,

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

; and Kopeysk, southern

Ural Mountains The Ural Mountains ( ),; , ; , or simply the Urals, are a mountain range in Eurasia that runs north–south mostly through Russia, from the coast of the Arctic Ocean to the river Ural (river), Ural and northwestern Kazakhstan.

, Russia. In the US it occurs at the Crestmore quarry,

Riverside County, California Riverside County is a County (United States), county located in the Southern California, southern portion of the U.S. state of California. As of the 2020 United States Census, 2020 census, its population was 2,418,185, making it the fourth-most ...

;

Tombstone, Arizona Tombstone is a city in Cochise County, Arizona, Cochise County, Arizona, United States, founded in 1879 by Prospecting, prospector Ed Schieffelin in what was then Pima County, Arizona, Pima County, Arizona Territory. It became one of the last ...

; Gabbs district,

Nye County, Nevada Nye County is a County (United States), county in the U.S. state of Nevada. As of the 2020 United States census, 2020 census, the population was 51,591. Its county seat is Tonopah, Nevada, Tonopah. At , Nye is Nevada's largest county by area ...

. In

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

, it occurs at Oka,

Quebec Quebec is Canada's List of Canadian provinces and territories by area, largest province by area. Located in Central Canada, the province shares borders with the provinces of Ontario to the west, Newfoundland and Labrador to the northeast, ...

and in

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, west of Cowell,

Eyre Peninsula The Eyre Peninsula is a triangular peninsula in South Australia. It is bounded by the Spencer Gulf on the east, the Great Australian Bight on the west, and the Gawler Ranges to the north. Earlier called Eyre's Peninsula, it was named after e ...

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

. The

crystal structure In crystallography, crystal structure is a description of ordered arrangement of atoms, ions, or molecules in a crystalline material. Ordered structures occur from intrinsic nature of constituent particles to form symmetric patterns that repeat ...

of periclase corresponds to that of

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 ...

and has been studied extensively due to its simplicity. As a consequence, the physical properties of periclase are well known, which makes the mineral a popular standard in experimental work. The mineral has been shown to remain stable at pressures up to at least 360

GPa Grading in education is the application of standardized measurements to evaluate different levels of student achievement in a course. Grades can be expressed as letters (usually A to F), as a range (for example, 1 to 6), percentages, or as num ...

Mantle occurrence

Ferropericlase makes up about 20% of the volume of the lower mantle of the Earth, which makes it the second most abundant mineral phase in that region after silicate

perovskite Perovskite (pronunciation: ) is a calcium titanium oxide mineral composed of calcium titanate (chemical formula ). Its name is also applied to the class of compounds which have the same type of crystal structure as , known as the perovskite (stru ...

; it also is the major host for iron in the lower mantle.Researchers locate mantle’s spin transition zone, leading to clues about earth’s structure
At the bottom of the transition zone of the mantle, the reaction : γ– transforms γ-olivine into a mixture of perovskite and ferropericlase and ''vice versa''. In the literature, this mineral phase of the lower mantle is also often called

magnesiowüstite Ferropericlase or magnesiowüstite is a magnesium/iron oxide with the chemical formula that is interpreted to be one of the main constituents of the Earth's lower mantle (Earth), lower mantle together with the silicate perovskite (), a magnesium/i ...

References

{{reflist Magnesium minerals Oxide minerals Cubic minerals Minerals in space group 225 Luminescent minerals Rocksalt group Minerals described in 1840