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The aluminosilicates — kyanite, andalusite, and sillimanite, all Al < sub > 2 </ sub > SiO </ sub > 5 </ sub >— are structurally composed of one < sup > 4 -</ sup > tetrahedron, and one Al < sup > 3 +</ sup > in octahedral coordination.
The remaining Al < sup > 3 +</ sup > can be in six-fold coordination ( kyanite ), five-fold ( andalusite ) or four-fold ( sillimanite ); which mineral forms in a given environment is depend on pressure and temperature conditions.
In the olivine structure, the main olivine series of ( Mg, Fe )< sub > 2 </ sub > SiO < sub > 4 </ sub > consist of magnesium-rich forsterite and iron-rich fayalite.
Both iron and magnesium are in octahedral by oxygen.
Other mineral species having this structure exist, such as tephroite, Mn < sub > 2 </ sub > SiO < sub > 4 </ sub >.
The garnet group has a general formula of X < sub > 3 </ sub > Y < sub > 2 </ sub >( SiO < sub > 4 </ sub >)< sub > 3 </ sub >, where X is a large eight-fold coordinated cation, and Y is a smaller six-fold coordinated cation.
There are six ideal endmembers of garnet, split into two group.
The pyralspite garnets have Al < sup > 3 +</ sup > in the Y position: pyrope ( Mg < sub > 3 </ sub > Al < sub > 2 </ sub >( SiO < sub > 4 </ sub >)< sub > 3 </ sub >, almandine ( Fe < sub > 3 </ sub > Al < sub > 2 </ sub >( SiO < sub > 4 </ sub >)< sub > 3 </ sub >), and spessartine ( Mn < sub > 3 </ sub > Al < sub > 2 </ sub >( SiO < sub > 4 </ sub >)< sub > 3 </ sub >).
The ugrandite garnets have Ca < sup > 2 +</ sup > in the X position: uvarovite ( Ca < sub > 3 </ sub > Cr < sub > 2 </ sub >( SiO < sub > 4 </ sub >)< sub > 3 </ sub >), grossular ( Ca < sub > 3 </ sub > Al < sub > 2 </ sub >( SiO < sub > 4 </ sub >)< sub > 3 </ sub >) and andradite ( Ca < sub > 3 </ sub > Fe < sub > 2 </ sub >( SiO < sub > 4 </ sub >)< sub > 3 </ sub >).
While there are two subgroups of garnet, solid solutions exists between all six end-members.

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