Olivine

The mineral olivine (when of gem-quality, it is also called peridot and chrysolite), is a magnesium iron silicate with the formula (Mg,Fe)2SiO4. It is a common mineral in the Earth's subsurface but weathers quickly on the surface.

The ratio of magnesium and iron varies between the two endmembers of the solid solution series: forsterite (Mg-endmember) and fayalite (Fe-endmember). Compositions of olivine are commonly expressed as molar percentages of forsterite (Fo) and fayalite (Fa) (e.g., Fo70Fa30). Forsterite has an unusually high melting temperature at atmospheric pressure, almost 1900 °C, but the melting temperature of fayalite is much lower (about 1200 °C). The melting temperature varies smoothly between the two endmembers, as do other properties. Olivine incorporates only minor amounts of elements other than oxygen, silicon, magnesium and iron. Manganese and nickel commonly are the additional elements present in highest concentrations.

Olivine gives its name to the group of minerals with a related structure (the olivine group) which includes tephroite (Mn2SiO4), monticellite (CaMgSiO4) and kirschsteinite (CaFeSiO4).

Read more about OlivineIdentification and Paragenesis, Crystal Structure, High Pressure Polymorphs, Weathering, Uses

Other articles related to "olivine":

Syrtis Major Quadrangle - Igneous Rocks
... Dacites form at the top of the chamber, after heavy minerals (olivine and pyroxene) containing iron and magnesium have settled to the bottom ... of Syrtis Major contain large amounts of the mineral olivine ... Olivine turns into other minerals very rapidly in the presence of water, so a high abundance of olivine suggests that for a long time little water has ...
Water On Mars - Findings By Probes - Mars Global Surveyor
... km2) area in the Nili Fossae formation that contains the mineral olivine ... the Isidis basin resulted in faults that exposed the olivine ... The discovery of olivine is strong evidence that parts of Mars have been extremely dry for a long time ...
Olivine - Uses
... Removal by reactions with olivine is an attractive option, because it is widely available and reacts easily with the (acid) CO2 from the atmosphere ... When olivine is crushed, it weathers completely within a few years, depending on the grain size ... CO2 that is produced by burning 1 liter of oil can be sequestered by less than 1 liter of olivine ...
Palisades Sill - Origin
... Due to the presence of the olivine-rich zone, the normally difficult task of determining the history of an igneous body becomes even tougher ... data and determined that there were at least two separate injections an olivine-rich magma was followed by normal tholeiitic basalt ... proposed at least three, but probably four separate pulses, with the olivine-rich magma being the final one ...
Limburgite
... They consist essentially of olivine and augite with a brownish glassy groundmass ... The augite may be green, but more commonly is brown or violet the olivine is usually pale green or colourless, but is sometimes yellow ... euhedral augites frequently occurs more rarely olivine is present also as an ingredient of the matrix ...