Definition
Arkose is a sedimentary rock, specifically a type of sandstone containing at least 25% feldspar
Anorthosite is a granular igneous rock composed largely of labradorite or plagioclase
History
Origin
France
-
Discoverer
Alexandre Brongniart
Unknown
Etymology
From Auvergne region of France used by a French geologist Alexandre Brongniart in 1826 who applied this term to some feldspathic sandstones
From French anorthose plagioclase + -ite1
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Plutonic
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock