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Phlogopite

 
Phlogopite

 
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Phlogopite
 
 
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Phlogopite is a yellow, greenish, or reddish-brown member of the mica
Mica

The mica group of sheet silicate minerals includes several closely related materials having highly perfect basal cleavage. All are monoclinic with a tendency towards pseudo-hexagonal crystals and are similar in chemical composition....
 family of phyllosilicates
Silicate minerals

The silicate minerals make up the largest and most important class of rock-forming minerals, comprising approximately 90 percent of the crust of the Earth....
. It is also known as magnesium
Magnesium

Magnesium is a chemical element with the symbol Mg, atomic number 12, atomic weight 24.3050 and common oxidation number +2.Magnesium, an alkaline earth metal, is the ninth most abundance of the chemical elements in the universe by mass....
 mica.

Phlogopite is the magnesium endmember of the biotite
Biotite

Biotite is a common Silicate minerals#Phyllosilicates mineral within the mica group, with the approximate chemical formula K3AlSi3O102....
 solid solution
Solid solution

A solid solution is a solid-phase solution of one or more soluble in a solvent. Such a mixture is considered a solution rather than a Chemical compound when the crystal structure of the solvent remains unchanged by addition of the solutes, and when the mixture remains in a single wiktionary:Homogeneous phase ....
 series, with the chemical formula K
Potassium

Potassium is a chemical element. It has the symbol K , atomic number 19, and atomic mass 39.0983. Potassium was first isolated from potash, hence the name....
Mg
Magnesium

Magnesium is a chemical element with the symbol Mg, atomic number 12, atomic weight 24.3050 and common oxidation number +2.Magnesium, an alkaline earth metal, is the ninth most abundance of the chemical elements in the universe by mass....
3AlSi
Silicon

Silicon is the most common metalloid. It is a chemical element, which has the symbol Si and atomic number 14. The atomic mass is 28.0855....
3O
Oxygen

Oxygen no O2 produced; 2) O2 produced, but absorbed in oceans & seabed rock; 3) O2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer; 4-5) O2 sinks filled and the gas accumulates]]...
10(F
Fluorine

Fluorine is the chemical element with the symbol F and atomic number 9. Fluorine forms a single bond with itself in elemental form, resulting in the diatomic F2 molecule....
,OH
Hydrogen

Hydrogen is the chemical element with atomic number 1. It is represented by the chemical symbol H. At standard temperature and pressure, hydrogen is a colorless, odorless, nonmetallic, tasteless, highly combustion and explosive Diatomic molecule gas with the molecular formula H2....
)2, or (KF
Potassium fluoride

Potassium fluoride is the chemical compound with the formula KF. After hydrogen fluoride, KF is the primary source of the fluoride ion for applications in manufacturing and in chemistry....
)2(MgO
Magnesia

Magnesia , deriving from the tribe name Magnetes, is the name of the southeastern area of Thessaly in central Greece. The modern prefecture was created in 1947 out of the Larissa prefecture....
)6(Al2O3
Aluminate

An aluminate is a compound containing aluminium and oxygen with more electropositive elements. Usually aluminate refers to AlO2-....
)(SiO2
Silicate

A silicate is a compound containing an anion in which one or more central silicon atoms are surrounded by electronegative ligands. This definition is broad enough to include species such as hexafluorosilicate , [SiF6]2-, but the silicate species that are encountered most often consist of silicon with oxygen as the ligand...
)6(H2O
Hydrate

Hydrate is a term used in inorganic chemistry and organic chemistry to indicate that a substance contains water. The chemical state of the water varies widely between hydrates, some of which were so labeled before their chemical structure was understood....
)2. For physical and optical identification, it shares most of the characteristic properties of the more-common biotite
Biotite

Biotite is a common Silicate minerals#Phyllosilicates mineral within the mica group, with the approximate chemical formula K3AlSi3O102....
, but lighter with a hint of olive green.

gopite is an important and relatively common end-member composition of biotite.






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Phlogopite is a yellow, greenish, or reddish-brown member of the mica
Mica

The mica group of sheet silicate minerals includes several closely related materials having highly perfect basal cleavage. All are monoclinic with a tendency towards pseudo-hexagonal crystals and are similar in chemical composition....
 family of phyllosilicates
Silicate minerals

The silicate minerals make up the largest and most important class of rock-forming minerals, comprising approximately 90 percent of the crust of the Earth....
. It is also known as magnesium
Magnesium

Magnesium is a chemical element with the symbol Mg, atomic number 12, atomic weight 24.3050 and common oxidation number +2.Magnesium, an alkaline earth metal, is the ninth most abundance of the chemical elements in the universe by mass....
 mica.

Phlogopite is the magnesium endmember of the biotite
Biotite

Biotite is a common Silicate minerals#Phyllosilicates mineral within the mica group, with the approximate chemical formula K3AlSi3O102....
 solid solution
Solid solution

A solid solution is a solid-phase solution of one or more soluble in a solvent. Such a mixture is considered a solution rather than a Chemical compound when the crystal structure of the solvent remains unchanged by addition of the solutes, and when the mixture remains in a single wiktionary:Homogeneous phase ....
 series, with the chemical formula K
Potassium

Potassium is a chemical element. It has the symbol K , atomic number 19, and atomic mass 39.0983. Potassium was first isolated from potash, hence the name....
Mg
Magnesium

Magnesium is a chemical element with the symbol Mg, atomic number 12, atomic weight 24.3050 and common oxidation number +2.Magnesium, an alkaline earth metal, is the ninth most abundance of the chemical elements in the universe by mass....
3AlSi
Silicon

Silicon is the most common metalloid. It is a chemical element, which has the symbol Si and atomic number 14. The atomic mass is 28.0855....
3O
Oxygen

Oxygen no O2 produced; 2) O2 produced, but absorbed in oceans & seabed rock; 3) O2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer; 4-5) O2 sinks filled and the gas accumulates]]...
10(F
Fluorine

Fluorine is the chemical element with the symbol F and atomic number 9. Fluorine forms a single bond with itself in elemental form, resulting in the diatomic F2 molecule....
,OH
Hydrogen

Hydrogen is the chemical element with atomic number 1. It is represented by the chemical symbol H. At standard temperature and pressure, hydrogen is a colorless, odorless, nonmetallic, tasteless, highly combustion and explosive Diatomic molecule gas with the molecular formula H2....
)2, or (KF
Potassium fluoride

Potassium fluoride is the chemical compound with the formula KF. After hydrogen fluoride, KF is the primary source of the fluoride ion for applications in manufacturing and in chemistry....
)2(MgO
Magnesia

Magnesia , deriving from the tribe name Magnetes, is the name of the southeastern area of Thessaly in central Greece. The modern prefecture was created in 1947 out of the Larissa prefecture....
)6(Al2O3
Aluminate

An aluminate is a compound containing aluminium and oxygen with more electropositive elements. Usually aluminate refers to AlO2-....
)(SiO2
Silicate

A silicate is a compound containing an anion in which one or more central silicon atoms are surrounded by electronegative ligands. This definition is broad enough to include species such as hexafluorosilicate , [SiF6]2-, but the silicate species that are encountered most often consist of silicon with oxygen as the ligand...
)6(H2O
Hydrate

Hydrate is a term used in inorganic chemistry and organic chemistry to indicate that a substance contains water. The chemical state of the water varies widely between hydrates, some of which were so labeled before their chemical structure was understood....
)2. For physical and optical identification, it shares most of the characteristic properties of the more-common biotite
Biotite

Biotite is a common Silicate minerals#Phyllosilicates mineral within the mica group, with the approximate chemical formula K3AlSi3O102....
, but lighter with a hint of olive green.

Paragenesis

Phlogopite is an important and relatively common end-member composition of biotite. Phlogopite micas are found primarily in igneous rocks, although it is also common in contact metamorphic
Metamorphic rock

Metamorphic rock is the result of the transformation of an existing rock type, the protolith, in a process called metamorphism, which means "change in form"....
 aureoles of intrusive
Intrusion

In geology, an intrusion is a body of igneous rock that has crystallized from molten magma below the surface of the Earth. Bodies of magma that solidify underground before they reach the surface of the earth are called plutons, named for Pluto , the Roman mythology of the underworld....
 igneous rock
Igneous rock

Igneous rock is one of the three main Rock types . Igneous rock is formed by magma being cooled and becoming solid . They may form with or without crystallization, either below the surface as Intrusion rocks or on the surface as extrusive rocks....
s with magnesian country rocks.

The occurrence of phlogopite mica within igneous rocks is difficult to constrain precisely because the primary control is rock composition as expected, but phlogopite is also controlled by conditions of crystallisation such as temperature, pressure, and vapor content of the igneous rock. Several igneous associations are noted: high-alumina basalt
Basalt

Basalt is a common extrusive volcanic rock. It is usually gray to black and fine-grained due to rapid cooling of lava at the surface of a planet....
s, ultrapotassic igneous rocks
Ultrapotassic igneous rocks

Ultrapotassic igneous rocks are a class of rare, volumetrically minor generally ultramafic or mafic silica-depleted igneous rocks.Ultrapotassic rocks are defined by molar potassium2oxygen/sodium2O >3 in much of the scientific literature....
, and ultramafic rock
Ultramafic rock

Ultramafic rocks are igneous rocks and metamorphic rocks-igneous rocks with very low silica content , generally >18% MagnesiumOxygen, high IronO, low potassium, and are composed of usually greater than 90% mafic minerals ....
s.

Basaltic association

The basaltic occurrence of phlogopite is in association with picrite basalt
Picrite basalt

Picrite basalt is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine. The rock type is also referred to as oceanite....
s and high-alumina basalts. Phlogopite is stable in basaltic compositions at high pressures and is often present as partially-resorbed phenocryst
Phenocryst

A phenocryst is a relatively large and usually conspicuous crystal distinctly larger than the grains of the rock Matrix of a porphyritic igneous rock....
s or an accessory phase in basalts generated at depth.

Ultrapotassic association

Phlogopite mica is a commonly known phenocryst and groundmass phase within ultrapotassic igneous rocks such as lamprophyre
Lamprophyre

Lamprophyres are uncommon, small volume ultrapotassic igneous rocks igneous rocks primarily occurring as Dike , lopoliths, laccoliths, stocks and small intrusions....
, kimberlite
Kimberlite

Kimberlite is a type of potassic volcanic rock best known for sometimes containing diamonds. It is named after the town of Kimberley, Northern Cape in South Africa, where the discovery of an diamond in 1871 spawned a diamond rush, eventually creating the Big Hole....
, lamproite
Lamproite

Lamproites are ultrapotassic igneous rocks earth's mantle-derived igneous rock. They have low CaO, Al2O3, Na2O, high K2O/Al2O3, a relatively high MgO content and extreme enrichment in incompatible elements....
, and other deeply-sourced ultramafic or high-magnesian melts. In this association phlogopite can form well preserved megacrystic plates to 10 cm, and is present as the primary groundmass mineral, or in association with pargasite amphibole, olivine, and pyroxene. Phlogopite in this association is a primary igneous mineral present because of the depth of melting and high vapor pressures.

Ultramafic rocks

Phlogopite is often found in association with ultramafic intrusions as a secondary alteration phase within metasomatic margins of large ultramafic to mafic layered intrusions
Ultramafic to mafic layered intrusions

Ultramafic to mafic layered intrusions are found in typically ancient cratons and are rare but worldwide in distribution. The intrusive complexes exhibit evidence of Fractional crystallization and crystal segregation by settling or floating of minerals from a melt....
. In some cases the phlogopite is considered to be produced by autogenic alteration during cooling. In other instances, metasomatism
Metasomatism

Metasomatism is the chemical alteration of a Rock by hydrothermal and other fluids.Metasomatism can occur via the action of hydrothermal fluids from an igneous or Metamorphism source....
 has resulted in phlogopite formation within large volumes, as in the ultramafic massif at Finero, Italy, within the Ivrea zone
Ivrea zone

The Ivrea zone is a tectonics terrane in the Italy Alps, that consists of a steeply Strike and dip piece of the Earth?s lower crust of the Apulian plate....
. Trace phlogopite, again considered the result of metasomatism, is common within coarse-grained peridotite
Peridotite

A peridotite is a dense, coarse-grained igneous rock, consisting mostly of the minerals olivine and pyroxene. Peridotite is ultramafic and ultrabasic, as the rock contains less than 45% silica....
 xenolith
Xenolith

A xenolith is a rock fragment which becomes enveloped in a larger rock during the latter's development and hardening. In geology, the term xenolith is almost exclusively used to describe inclusions in igneous rock during magma emplacement and eruption....
s carried up by kimberlite
Kimberlite

Kimberlite is a type of potassic volcanic rock best known for sometimes containing diamonds. It is named after the town of Kimberley, Northern Cape in South Africa, where the discovery of an diamond in 1871 spawned a diamond rush, eventually creating the Big Hole....
, and so phlogopite appears to be a common trace mineral in the uppermost part of the Earth's mantle. Phlogopite is encountered as a primary igneous phenocryst
Phenocryst

A phenocryst is a relatively large and usually conspicuous crystal distinctly larger than the grains of the rock Matrix of a porphyritic igneous rock....
 within lamproite
Lamproite

Lamproites are ultrapotassic igneous rocks earth's mantle-derived igneous rock. They have low CaO, Al2O3, Na2O, high K2O/Al2O3, a relatively high MgO content and extreme enrichment in incompatible elements....
s and lamprophyres, the result of highly fluid-rich melt compositions within the deep mantle.