Definition
Rhyolite is a fine-grained igneous rock which is rich in silica
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
History
Origin
North America
Germany
Discoverer
Ferdinand von Richthofen
Van Tooren
Etymology
From German Rhyolit, from Greek rhuax lava stream + lithos stone
From Greek tephra, ashes from Indo-European base, to burn
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
Volcanic
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock