Green sand for aluminum typically uses olivine sand ( a mixture of the minerals forsterite and fayalite, which is made by crushing dunite rock ).
22.
For instance in mafic and ultramafic melts, the MgO and SiO 2 contents determine whether forsterite olivine is precipitated or whether enstatite pyroxene is precipitated.
23.
Component chemicals found at Lascar include : anorthite, augite bordering on diopside, bronzite, fassaite, forsterite, hypersthene, pigeonite, and more.
24.
"' Wadsleyite "'is a high-pressure phase of Mg 2 SiO 4 and is polymorphous with the olivine phase forsterite.
25.
It is commonly occurs in rocks that contain calcite, quartz, tremolite, witherite, phlogopite, diopside, minor amounts of forsterite and taramellite.
26.
Lazurite is a product of contact metamorphism of limestone and typically is associated with calcite, pyrite, diopside, humite, forsterite, hauyne and muscovite.
27.
In the olivine structure, the main olivine series of ( Mg, Fe ) 2 SiO 4 consist of magnesium-rich forsterite and iron-rich fayalite.
28.
Compositions of olivine are commonly expressed as molar percentages of forsterite ( Fo ) and fayalite ( Fa ) ( e . g ., Fo 70 Fa 30 ).
29.
"Spitzer " observations, announced in May 2011, indicate that tiny forsterite crystals might be falling down like rain on to the protostar HOPS-68.
30.
MgO and SiO 2 concentrations in melts are among the variables that determine whether forsterite olivine or enstatite pyroxene is precipitated, but the water content and pressure are also important.
