Definition
Variolites are a group of dark green basic igneous rocks which exhibit pale colored spots, or spherules, especially on weathered surfaces, that give them a pockmarked appearance
Rhyolite is a fine-grained igneous rock which is rich in silica
History
Origin
France
North America
Discoverer
Unknown
Ferdinand von Richthofen
Etymology
From Latin varius, speckled, variegated
From German Rhyolit, from Greek rhuax lava stream + lithos stone
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
Volcanic
Other Categories
Opaque Rock
Coarse Grained Rock, Opaque Rock