Periclase
Encyclopedia
Periclase occurs naturally in contact metamorphic rock
Metamorphic rock
Metamorphic rock is the transformation of an existing rock type, the protolith, in a process called metamorphism, which means "change in form". The protolith is subjected to heat and pressure causing profound physical and/or chemical change...

s and is a major component of most basic refractory
Refractory
A refractory material is one that retains its strength at high temperatures. ASTM C71 defines refractories as "non-metallic materials having those chemical and physical properties that make them applicable for structures, or as components of systems, that are exposed to environments above...

 bricks. It is a cubic
Cubic crystal system
In crystallography, the cubic crystal system is a crystal system where the unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals....

 form of magnesium oxide
Magnesium oxide
Magnesium oxide , or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium . It has an empirical formula of and consists of a lattice of Mg2+ ions and O2– ions held together by ionic bonds...

 (Mg
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...

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...

).

It was first described in 1840 and named from the Greek περικλάω (to break around) in allusion to its cleavage. The type locality
Type locality (geology)
Type locality , also called type area or type locale, is the where a particular rock type, stratigraphic unit, fossil or mineral species is first identified....

 is Monte Somma, Somma-Vesuvius Complex, Naples Province, Campania
Campania
Campania is a region in southern Italy. The region has a population of around 5.8 million people, making it the second-most-populous region of Italy; its total area of 13,590 km² makes it the most densely populated region in the country...

, Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

.

The old term for the mineral is magnesia. Stones from the Magnesia
Magnesia on the Maeander
Magnesia or Magnesia on the Maeander was an ancient Greek city in Anatolia, considerable in size, at an important location commercially and strategically in the triangle of Priene, Ephesus and Tralles. The city was named Magnesia, after the Magnetes from Thessaly who settled the area along with...

 region in ancient Anatolia
Anatolia
Anatolia is a geographic and historical term denoting the westernmost protrusion of Asia, comprising the majority of the Republic of Turkey...

 contained both magnesium oxide and hydrated magnesium carbonate
Magnesium carbonate
Magnesium carbonate, MgCO3, is a white solid that occurs in nature as a mineral. Several hydrated and basic forms of magnesium carbonate also exist as minerals...

 as well as iron oxide
Iron oxide
Iron oxides are chemical compounds composed of iron and oxygen. All together, there are sixteen known iron oxides and oxyhydroxides.Iron oxides and oxide-hydroxides are widespread in nature, play an important role in many geological and biological processes, and are widely utilized by humans, e.g.,...

s (such as magnetite
Magnetite
Magnetite is a ferrimagnetic mineral with chemical formula Fe3O4, one of several iron oxides and a member of the spinel group. The chemical IUPAC name is iron oxide and the common chemical name is ferrous-ferric oxide. The formula for magnetite may also be written as FeO·Fe2O3, which is one part...

). Thus these stones, called Stones from Magnesia in antiquity, with their unusual magnetic properties were the reason the terms magnet
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, and attracts or repels other magnets.A permanent magnet is an object...

and magnetism
Magnetism
Magnetism is a property of materials that respond at an atomic or subatomic level to an applied magnetic field. Ferromagnetism is the strongest and most familiar type of magnetism. It is responsible for the behavior of permanent magnets, which produce their own persistent magnetic fields, as well...

were coined.

Periclase is usually found in marble
Marble
Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite.Geologists use the term "marble" to refer to metamorphosed limestone; however stonemasons use the term more broadly to encompass unmetamorphosed limestone.Marble is commonly used for...

 produced by metamorphism
Metamorphism
Metamorphism is the solid-state recrystallization of pre-existing rocks due to changes in physical and chemical conditions, primarily heat, pressure, and the introduction of chemically active fluids. Mineralogical, chemical and crystallographic changes can occur during this process...

 of dolomitic
Dolomite
Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone....

 limestones. It readily alters to brucite
Brucite
Brucite is the mineral form of magnesium hydroxide, with the chemical formula Mg2. It is a common alteration product of periclase in marble; a low-temperature hydrothermal vein mineral in metamorphosed limestones and chlorite schists; and formed during serpentinization of dunites...

 under near surface conditions.

In addition to its type locality, it is reported from Predazzo
Predazzo
Predazzo is a comune of c. 4,400 inhabitants in Trentino in the northern Italian region Trentino-Alto Adige/Südtirol, located about 45 km northeast of Trento in the Val di Fiemme, at the confluence of the Travignolo stream with that Avisio River.The municipality of Predazzo contains the...

, Tyrol
Tyrol (state)
Tyrol is a state or Bundesland, located in the west of Austria. It comprises the Austrian part of the historical region of Tyrol.The state is split into two parts–called North Tyrol and East Tyrol–by a -wide strip of land where the state of Salzburg borders directly on the Italian province of...

, Austria
Austria
Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...

; Carlingford, County Louth
Carlingford, County Louth
Carlingford is a coastal town and townland in northern County Louth, Ireland. It is situated between Carlingford Lough and Slieve Foy, sometimes known as Carlingford Mountain...

, Ireland; Broadford, Skye
Broadford, Skye
Broadford , together with nearby Harrapool, is the second-largest settlement on the Isle of Skye, Scotland, lying on the SW corner of Broadford Bay, on the A87 between Portree and the Skye Bridge....

 and the island of Muck
Muck, Scotland
Muck is the smallest of four main islands in the Small Isles, part of the Inner Hebrides of Scotland. It measures roughly 2.5 miles east to west and has a population of around 30, mostly living near the harbour at Port Mòr. The other settlement on the island is the farm at Gallanach...

, Scotland; León
León (province)
León is a province of northwestern Spain, in the northwestern part of the autonomous community of Castile and León.About one quarter of its population of 500,200 lives in the capital, León. The weather is cold and dry during the winter....

, Spain; the Bellerberg volcano, Eifel
Eifel
The Eifel is a low mountain range in western Germany and eastern Belgium. It occupies parts of southwestern North Rhine-Westphalia, northwestern Rhineland-Palatinate and the south of the German-speaking Community of Belgium....

 district, Germany; Nordmark and Långban
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 birthplace of Swedish-American inventor John EricssonIt has...

, Varmland
Värmland
' is a historical province or landskap in the west of middle Sweden. It borders Västergötland, Dalsland, Dalarna, Västmanland and Närke. It is also bounded by Norway in the west. Latin name versions are Vermelandia and Wermelandia. Although the province's land originally was Götaland, the...

, Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

; and Kopeysk
Kopeysk
Kopeysk is a city in Chelyabinsk Oblast, Russia, located southeast of Chelyabinsk. Population: The population growth of the city between 2002 and 2010 was caused by the annexation of surrounding settlements....

, southern Ural Mountains
Ural Mountains
The Ural Mountains , or simply the Urals, are a mountain range that runs approximately from north to south through western Russia, from the coast of the Arctic Ocean to the Ural River and northwestern Kazakhstan. Their eastern side is usually considered the natural boundary between Europe and Asia...

, Russia. In the USA it occurs at the Crestmore quarry, Riverside County, California
Riverside County, California
Riverside County is a county in the U.S. state of California. One of 58 California counties, it covers in the southern part of the state, and stretches from Orange County to the Colorado River, which forms the state border with Arizona. The county derives its name from the city of Riverside,...

; Tombstone, Cochise County, Arizona
Cochise County, Arizona
-2010:Whereas according to the 2010 U.S. Census Bureau:*78.5% White*4.2% Black*1.2% Native American*1.9% Asian*0.3% Native Hawaiian or Pacific Islander*4.0% Two or more races*9.6% Other races*32.4% Hispanic or Latino -2000:...

; Gabbs district, Nye County, Nevada
Nye County, Nevada
-National protected areas:* Ash Meadows National Wildlife Refuge* Death Valley National Park * Humboldt-Toiyabe National Forest * Spring Mountains National Recreation Area -Demographics:...

. In Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

, it occurs at Oka
Oka
Oka or OKA may refer to:* Oka , a Canadian cheese* Oka , an Ottoman unit of weight equal to 1.2829 kilograms* Oca or Oca, the root vegetable Oxalis tuberosa* MXY-7 Ohka , a Japanese kamikaze aircraft in World War II...

, Quebec
Quebec
Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....

 and in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, west of Cowell
Cowell, South Australia
Cowell is a coastal town on Franklin Harbour on the eastern side of the Eyre Peninsula, in South Australia on the Lincoln Highway 111 km south from the major town of Whyalla...

, Eyre Peninsula
Eyre Peninsula
Eyre Peninsula is a triangular peninsula in South Australia. It is bounded on the east by Spencer Gulf, the west by the Great Australian Bight, and the north by the Gawler Ranges. It is named after explorer Edward John Eyre who explored some of it in 1839-1841. The coastline was first explored by...

, South Australia
South Australia
South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...

.
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