Definition
Phonolite is an uncommon extrusive igneous rock volcanic rock of intermediate chemical composition between felsic and mafic
Trachyandesite is an extrusive igneous rock.
History
Origin
-
Indonesia
Discoverer
Unknown
Unknown
Etymology
From the Greek meaning sounding stone because of the metallic sound it produces if an unfractured plate is hit
From French trachyandésite, trachy + andésite andesite, a lava intermediate in composition between trachyte and andesite
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock