Feldspar

 

Feldspars (KAlSi3O8  NaAlSi3O8  CaAl2Si2O8) are a group of rock-forming tectosilicate minerals that make up as much as 60% of the Earth's crust.

 

Feldspars crystallize from magma in both intrusive and extrusive igneous rocks, as veins, and are also present in many types of metamorphic rock. Rock formed almost entirely of calcic plagioclase feldspar (see below) is known as anorthosite. Feldspars are also found in many types of sedimentary rock.

 

 

For further information, please click on the link below:

http://en.wikipedia.org/wiki/Feldspar 

 

 

 



Source:

 

Wikipedia, The Free Encyclopedia

 

 


 

 

 

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