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Related to olivine: pyroxene


(ŏlĭv`ēn), an iron-magnesium silicate mineral, (Mg,Fe)2SiO4, crystallizing in the orthorhombic system. It is a common constituent of magnesium-rich, silica-poor igneous rocks; metamorphism of some high magnesium sediments also can form olivine. Dunite consists almost entirely of olivine. It also occurs in lunar rocks and meteorites. Olivine has a characteristic yellow-green to olive-green color, hence the name. Transparent olivine of good color can be cut into gemstones; the gem form is known as peridot. Sources of gem-quality olivine are St. John's Island in the Red Sea, Myanmar, and Arizona. Magnesium-rich olivine has a high melting point and is used in the manufacture of refractories. It was formerly called chrysolite.



(also peridot or chrysolite), a mineral of the neso-silicate class; the main representative of the olivine group. The olivine group includes forsterite, Mg2[SiO4]; olivine, (Mg,Fe)2[SiO4]; fayalite, Fe2[SiO4]; tephroite, Mn2[SiO4]; knebelite, (Fe,Mn)2[SiO4]; and monticellite, CaMg[SiO4].

The minerals of the olivine group differ from one another in both properties and composition. They crystallize in the ortho-rhombic system to form tabular or prismatic crystals. The olivine structure is composed of isolated tetrahedral SiO44- groups and of Mg2+ and Fe2+ cations surrounded by six oxygen ions. The structural distribution of magnesium and iron, as determined by Mössbauer spectra, serves as a geothermometer. Olivine has imperfect cleavage; its hardness on Mohs’ scale is 6.5–7.0, and its density is 3,200–4,400 kg/m3, depending on the number of heavy iron and manganese atoms per molecule. Its color varies from yellowish green to olive green; sometimes the mineral is colorless.

Olivine is widespread in nature as a rock-forming mineral in ultrabasic and basic rocks, such as dunites, peridotites, olivine gabbros, diabases, and basalts, including lunar basalt. The olivine structure rearranges to form a spinel-type lattice under high pressure (130–160 kilobars). The effect of hydrothermal solutions readily alters olivine into serpentine and sometimes also to talc. On the earth’s surface, olivine decomposes to yield magne-site, hydrous iron oxides, and opal. Transparent olivine crystals, or chrysolites, are precious stones.


Mineraly: Spravochnik, vol. 3, fasc. 1. Moscow, 1972.


(Mg,Fe2)SiO4 A neosilicate group of olive-green magnesium-iron silicate minerals crystallizing in the orthorhombic system and having a vitreous luster; hardness is 6½-7 on Mohs scale; specific gravity is 3.27-3.37.
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Group Members of ADS are Ameren, American Public Power Association, Arizona Public Service, California ISO, Comverge, Con Edison, Conservation Services Group, Constellation, Corporate Systems Engineering, Dimplex, Duke Energy, Emerson Climate Technologies, ENBALA, Energate, EnergyHub, EnerNOC, Freeman, Sullivan & Co, GE, ISO New England, Landis+Gyr, MISO, National Grid, National Rural Electric Cooperative Association, Navigant Energy Practice, Negawatt, NYSERDA, Olivine, Inc.
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Thin section examination of the xenoliths revealed pyroxenes intermix with olivine.
Early olivine, pyroxene, chromite and immiscible sulfide formation cause compatible elements (e.
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5 kg, were crushed and separated into heavy mineral concentrates (HMC) from which garnet, clinopyroxene, orthopyroxene, olivine, ilmenite and chromite indicator minerals were picked and analysed by electron microprobe at a commercial laboratory.
Phenocryst-poor latite and trachyte are interpreted as the result of mineral separation, and phenocryst-rich tephrite porphyry and olivine diabase porphyry are the result of phenocryst accumulations in the magma chamber.
During the splitting process, a mineral called serpentine is formed when the olivine mineral strips one oxygen and hydrogen atom from an H2O molecule to release the spare hydrogen atom.
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For the moment the rock bears the name OOS, because it is rich in the minerals orthopyroxene, olivine and spinel.