Definition
Rhyolite is a fine-grained igneous rock which is rich in silica
Jasperoid is a rare, peculiar type of metasomatic alteration of rocks
History
Origin
North America
USA
Discoverer
Ferdinand von Richthofen
Unknown
Etymology
From German Rhyolit, from Greek rhuax lava stream + lithos stone
From silica, the main mineral content of Jasperoid
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
-
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock