Definition
Arkose is a sedimentary rock, specifically a type of sandstone containing at least 25% feldspar
Dunite is a green to brownish coarse-grained igneous rock mainly consisting of olivine
History
Origin
France
New Zealand
Discoverer
Alexandre Brongniart
Ferdinand von Hochstetter
Etymology
From Auvergne region of France used by a French geologist Alexandre Brongniart in 1826 who applied this term to some feldspathic sandstones
From the name of Dun Mountain, New Zealand, + -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