Fandom

Geology Wiki

Anorthite

518pages on
this wiki
Add New Page
Talk0 Share

Template:Infobox mineral Anorthite is the calcium endmember of plagioclase feldspar. Plagioclase is an abundant mineral in the Earth's crust. The formula of pure anorthite is CaAl2Si2O8.

Mineralogy Edit

File:Anorthite-221029.jpg

Anorthite is the calcium-rich endmember of the plagioclase solid solution series, the other endmember being albite, NaAlSi3O8. Anorthite also refers to plagioclase compositions with more than 90 molecular percent of the anorthite endmember.

OccurrenceEdit

Anorthite is a rare compositional variety of plagioclase. It occurs in mafic igneous rock. It also occurs in granulite facies metamorphic rocks, in metamorphosed carbonate rocks and corundum deposits.[1] Its type localities are Monte Somma and Valle di Fassa, Italy. It was first described in 1823.[2] It is more rare in surficial rocks than it normally would be due to its high weathering potential in the Goldich dissolution series.

It also makes up much of the lunar highlands; the Genesis Rock is made of anorthosite, which is composed largely of anorthite. Anorthite was discovered in samples from comet Wild 2, and the mineral is an important constituent of Ca-Al-rich inclusions in rare varieties of chondritic meteorites.

See also Edit

References Edit

Template:Commonscat Template:Reflist


Cite error: <ref> tags exist, but no <references/> tag was found

Ad blocker interference detected!


Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.