Share on Facebook Share on Twitter Email
Answers.com

albite

 
Dictionary: al·bite   (ăl'bīt) pronunciation
n.
A widely distributed white feldspar, NaAlSi3O8, that is one of the common rock-forming plagioclase group.

[Latin albus, white + -ITE1.]

albitic al·bit'ic (-bĭt'ĭk) or al·bit'i·cal (-ĭ-kəl) adj.

Search unanswered questions...
Enter a question here...
Search: All sources Community Q&A Reference topics

Common feldspar mineral, a sodium aluminosilicate (NaAlSi3O8) that occurs most widely in pegmatites and acid igneous rocks such as granites. It may also be found in low-grade metamorphic rocks (those formed under relatively low temperature and pressure conditions) and in certain sedimentary rocks. Albite usually forms brittle, glassy crystals that may be colourless, white, yellow, pink, green, or black. It is used in the manufacture of glass and ceramics, but its primary geologic importance is as a rock-forming mineral.

For more information on albite, visit Britannica.com.

A sodium-rich plagioclase feldspar mineral whose composition extends over the range Ab100An0 to Ab90An10, where Ab (= albite) is NaAlSi3O8 and An (= anorthite) is CaAl2Si2O8. Albite occurs in crustal igneous rocks as a major component of pegmatites and granites, in association with quartz, mica (usually muscovite), and potassium feldspar (orthoclase or microcline). Sodium and potassium feldspars usually occur as distinct mineral grains, sizes varying from millimeter to meter scale. They are frequently intergrown; if the intergrowth is visually observable in a hand specimen, the composite material is known as macroperthite; if visible only in a microscope, microperthite; and if submicroscopic in scale, cryptoperthite. In metamorphic rocks albite is found in granitic gneisses, and it may be the principal component of arkose, a feldspar-dominant, sedimentary rock. Cleavelandite, a platy variety, is sometimes found in lithium-rich pegmatites. See also Arkose; Feldspar; Gneiss; Igneous rocks; Pegmatite; Perthite.


WordNet: albite
Top
Note: click on a word meaning below to see its connections and related words.

The noun has one meaning:

Meaning #1: a widely distributed rock-forming feldspar
  Synonym: white feldspar


Wikipedia: Albite
Top
Albite

Albite
General
Category plagioclase, feldspar, tectosilicate
Chemical formula NaAlSi3O8
Identification
Color generally white
Crystal habit pinacoidal forms
Crystal system triclinic
Mohs scale hardness 6 - 6.5
Specific gravity ~2.62
Albite

Albite is a plagioclase feldspar mineral. It is the sodium endmember of the plagioclase 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. Its color is usually pure white, hence its name from Latin albus.

Albite crystallizes with triclinic pinacoidal forms. Its specific gravity is about 2.62 and it has a Mohs hardness of 6 - 6.5. Albite almost always exhibits crystal twinning often as minute parallel striations on the crystal face. Albite often occurs as fine parallel segregations alternating with pink microcline in perthite as a result of exolution on cooling. It occurs in granitic and pegmatite masses, in some hydrothermal vein deposits and forms part of the typical greenschist metamorphic assemblage for rocks of originally basaltic composition.

It was first reported in 1815 for an occurrence in Sweden. The name is from Latin, albus for the typical white color.

References


 
 
Learn More
albitophyre (petrology)
albitization (petrology)
keratophyre (petrology)

Where can you find albite? Read answer...
Is albite also known as lime feldspar? Read answer...

Help us answer these
Is albite-anorthite solid solution present in the binary system ofalbite-orthoclase system?
What is the texture of the albite?
How is albites mined?

Post a question - any question - to the WikiAnswers community:

 

Copyrights:

Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.  Read more
Britannica Concise Encyclopedia. Britannica Concise Encyclopedia. © 2006 Encyclopædia Britannica, Inc. All rights reserved.  Read more
Sci-Tech Encyclopedia. McGraw-Hill Encyclopedia of Science and Technology. Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved.  Read more
WordNet. WordNet 1.7.1 Copyright © 2001 by Princeton University. All rights reserved.  Read more
Wikipedia. This article is licensed under the Creative Commons Attribution/Share-Alike License. It uses material from the Wikipedia article "Albite" Read more