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The mineral olivine (/ ˈ ɒ l. ɪ ˌ v iː n /) is a magnesium iron silicate with the chemical formula (Mg,Fe) 2 Si O 4.It is a type of nesosilicate or orthosilicate.The primary component of the Earth's upper mantle, [9] it is a common mineral in Earth's subsurface, but weathers quickly on the surface.
Enstatite is a mineral; the magnesium endmember of the pyroxene silicate mineral series enstatite (MgSiO 3) – ferrosilite (FeSiO 3).The magnesium rich members of the solid solution series are common rock-forming minerals found in igneous and metamorphic rocks.
Clinohumite is an uncommon member of the humite group, a magnesium silicate according to the chemical formula (Mg, Fe) 9 (Si O 4) 4 (F,OH) 2.The formula can be thought of as four olivine (Mg 2 SiO 4), plus one brucite (Mg(OH) 2).
Olivine lamproites are ultrapotassic, peralkaline rocks rich in volatiles (dominantly H 2 O). The distinctive characteristic of olivine lamproites is phlogopite macrocrysts and microphenocrysts, together with groundmass micas that vary in composition from phlogopite to "tetraferriphlogopite" (anomalously Al-poor phlogopite requiring Fe to enter ...
A rock consisting of 80% olivine, 5% magnetite and 15% groundmass is an olivine mesocumulate, (in essence a peridotite). Cumulate terminology is appropriate for use when describing cumulate rocks. In intrusions which have a uniform composition and minimal textural and mineralogical layering or visible crystal accumulations it is inappropriate ...
It includes olivine-gabbro, olivine–dolerite, olivine-basalt, and peridotites, among others. Ordovician A geologic period and system, the second of six of the Paleozoic Era, spanning the time between 485.4 ± 1.9 to 443.4 ± 1.5 million years ago. It follows the Cambrian and is followed by the Silurian. orogenesis
Serpentine minerals are often formed by the hydration of olivine-rich ultramafic rocks at relatively low temperatures (0 to ~600 °C). [15] The chemical reaction turns olivine into serpentine minerals. They may also have their origins in metamorphic alterations of peridotite and pyroxene.
Tephroite is the manganese endmember of the olivine group of nesosilicate minerals with the formula Mn 2 Si O 4. A solid solution series exists between tephroite and its analogues, the group endmembers fayalite and forsterite. Divalent iron or magnesium may readily replace manganese in the olivine crystal structure.