Definition
Phonolite is an uncommon extrusive igneous rock volcanic rock of intermediate chemical composition between felsic and mafic
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
History
Origin
-
Germany
Discoverer
Unknown
Van Tooren
Etymology
From the Greek meaning sounding stone because of the metallic sound it produces if an unfractured plate is hit
From Greek tephra, ashes from Indo-European base, to burn
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Family
Group
-
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock