Definition
Arkose is a sedimentary rock, specifically a type of sandstone containing at least 25% feldspar
Rapakivi Granite is a hornblende-biotite Granite containing large rounded crystals of orthoclase which are mantled with oligoclase
History
Origin
France
Finland, Europe
Discoverer
Alexandre Brongniart
Jakob Sederholm
Etymology
From Auvergne region of France used by a French geologist Alexandre Brongniart in 1826 who applied this term to some feldspathic sandstones
From Finnish Rapakivi which stands for crumbly rock
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
-
Plutonic
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock