Definition
Rhyolite is a fine-grained igneous rock which is rich in silica
Felsite is a very fine grained volcanic rock that may or may not contain larger crystals and light colored rock that typically requires petrographic examination or chemical analysis for more precise definition
History
Origin
North America
-
Discoverer
Ferdinand von Richthofen
Unknown
Etymology
From German Rhyolit, from Greek rhuax lava stream + lithos stone
From English feldspar and -ite
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
Volcanic
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock