- Albite
Albite is a plagioclase
feldspar mineral . It is the sodium endmember of theplagioclase solid solution series. As such it represents a plagioclase with less than 10%anorthite content. The pure albite endmember has the formula NaAlSi3O8. It is a tectosilicate.Albite crystallizes with
triclinic pinacoidal forms. Itsspecific gravity is about 2.62 and it has aMohs hardness of 6 - 6.5. Albite almost always exhibitscrystal twinning often as minute parallel striations on the crystal face. Albite often occurs as fine parallel segregations alternating with pinkmicrocline inperthite as a result of exolution on cooling.It occurs ingranitic andpegmatite masses, in somehydrothermal vein deposits and forms part of the typicalgreenschist metamorphic assemblage for rocks of originally basaltic composition.It was first reported in 1815 for an occurrence in
Sweden . The name is fromLatin , "albus" for the typical white color.References
* [http://www.mindat.org/min-96.html Mindat data]
* [http://www.webmineral.com/data/Albite.shtml Webmineral data]
* [http://mineral.galleries.com/minerals/silicate/albite/albite.htm Mineral galleries]
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