Anorthosite
A rock classification type
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About Anorthosite
A coarse-grained crystalline rock consisting mostly of calcic plagioclase (>90%, usually labradorite) with <10% mafics. The mafic mineral may be clinopyroxene, orthopyroxene, olivine, or, more rarely, amphibole. Oxides, mostly magnetite or ilmenite, are also common.
The lunar highlands are composed predominantly of anorthosite.
The lunar highlands are composed predominantly of anorthosite.
Unique Identifiers
Mindat ID:
48323
Long-form identifier:
mindat:1:1:48323:6
Similar Names
| Anorthoîte | A synonym of Anorthite |
Classification of Anorthosite
Anorthosite is in section 10 of the QAPF diagram.
Sub-divisions of Anorthosite
Mineralogy of Anorthosite
Essential minerals - these are minerals that are required within the classification of this rock:
| Feldspar > Plagioclase | (Na,Ca)[(Si,Al)AlSi2]O8 |
Non-essential minerals - these minerals are common, sometimes major components, but are not always present:
| Pyroxene | A petrological term for Pyroxene Group. |
Synonyms of Anorthosite
Common Associates
Associations Based on Photo Data:
| 1 photo of Anorthosite associated with 'Pyroxenite' | |
| 1 photo of Anorthosite associated with 'Pegmatite' | |
| 1 photo of Anorthosite associated with 'Sulfide ore' | |
| 1 photo of Anorthosite associated with Plagioclase | (Na,Ca)[(Si,Al)AlSi2]O8 |
| 1 photo of Anorthosite associated with Orthopyroxene Subgroup | |
| 1 photo of Anorthosite associated with 'Labradorite' | (Ca,Na)[Al(Al,Si)Si2O8] |
Internet Links for Anorthosite
mindat.org URL:
https://www.mindat.org/min-48323.html
Please feel free to link to this page.
Please feel free to link to this page.
References for Anorthosite
Reference List:
Elizondo-Pacheco, L.A., Solari, L.A., González-Guzmán, R., He, H.L., Becerra-Torres, E., RamĂrez-Fernández, J.A., Maldonado, R. (2024) Multi-isotope and geochemical approach to the magma source and tectonic setting of Proterozoic anorthosite massifs and Anorthosite-Mangerite-Charnockite-Granite (AMCG) suites. Geoscience Frontiers, 15 (6). doi:10.1016/j.gsf.2024.101880
Alma quarry, Lac-Saint-Jean-Est RCM, Saguenay-Lac-Saint-Jean, Québec, Canada