Definition
Andesite is a dark, fine-grained, brown or greyish intermediate volcanic rock which is a commonly found in lava
Phonolite is an uncommon extrusive igneous rock volcanic rock of intermediate chemical composition between felsic and mafic
History
Origin
North America
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Discoverer
Theodor von Gümbel
Unknown
Etymology
From Andes mountains, where it is found in abundance
From the Greek meaning sounding stone because of the metallic sound it produces if an unfractured plate is hit
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
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Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock