Definition
Rhyolite is a fine-grained igneous rock which is rich in silica
Arkose is a sedimentary rock, specifically a type of sandstone containing at least 25% feldspar
History
Origin
North America
France
Discoverer
Ferdinand von Richthofen
Alexandre Brongniart
Etymology
From German Rhyolit, from Greek rhuax lava stream + lithos stone
From Auvergne region of France used by a French geologist Alexandre Brongniart in 1826 who applied this term to some feldspathic sandstones
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
-
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock